Linux

1. Not really unless you're hyper-focused on a very specific type of performance. Even then, you can always enable/disable whatever bits and pieces because it's all software, and it's all open. There are guides or threads for absolutely everything out there. A distro only organizes it simpler on base install to make it easier ootb.

2. Linux itself does not do any data collection. Never heard of any distro enabling anything by default, and you can rip it right out anyway if you want, though it's more work. If you're concerned about this though, stay away from Ubuntu, as that is the one corporate backed distro that is more likely to lean into this.

3. Fedora is probably what you want. It's taken over the helm Ubuntu used to have as the default to try. Clean, simple, no bullshit, huge community.

4. Linux, no, but you're conflating a few things. Linux is the kernel. The desktop you choose to run is what does the graphical session management. Both KDE and Gnome are fine with this, though there is an argument that KDE is a tad ahead in this realm with their VRR implementation.

5. Gnome is more akin to MacOS. KDE is more Windows-like (but still not at all). Try both on a liveUSB for a bit and see which you like.

At the end of the day you can run practically anything on a liveUSB for as long as you want before installing, even games (within reason). Be comfortable in the knowledge that if there is something you don't like about a particular thing, you can change it to act however you want. Like I said above, it's all just software. It's going to be a little tough coming from a Windows-centric world to realize this at first, but I assure you, installing and running one distro absolutely does not lock you into anything at all because you can just install and remove absolutely everything.

Now, hardware compatibility is a different story. The Linux kernel itself is what does all the hardware management, so if your hardware is too new, there may not be full support for a particular thing. It sounds like you're on an older machine though, so unless it's got some really obscure hardware in it, everything should be detected and load straight out of the box. Again, try a few liveUSB runs and make sure, it's that simple.

Distros matter. Maybe less than you think.

For the most part, they all run the same software, including the desktop environment (user experience).

So, in many ways, choosing your distro is mostly choosing how it comes out of the box and how much work it will be to configure it how you want after the fact. Some distros will be closer to what you want out of the box. But you can basically turn any distro into any other distro with a little effort.

That said, some choices do run a bit deeper and are a lot harder to change. Package manager, init system, C library, and others are pretty baked in.

1. the distro matters, but as a general rule, start with mint cinnamon because it's easy and super stable. different distros use different components and they are configured differently, so if you face issues and incompatibility on mint, fedora may work better for example. for me it's the other way around. also on debian or ubuntu based distros you have the biggest selection of programs available. not sure what packages you are referring to..just applications in general? it's as easy as just installing or uninstalling them from your package manager / software center or whatever.

2. ubuntu is owned by canonical, I'd say avoid that. mint is derived from ubuntu, but it has a debian edition so it's not threatened if ubuntu gets further enshittified.

3. I recently used kububtu for a week, something to note: it's running very far behind, using plasma 5.27. in my experience, kde in general seems to have lots of customization but a lot of it is just broken. all the themes you can find, most won't install, animations are laggy (I suspect nvidia issue). downvotes incoming, but that's just my experience. it may work for you though idk. fedora official and pop use gnome, which I have very limited experience with, but I remember it not giving too much control to the user with customization if that's what you're after, also what's with the full screen app launcher? in cinnamon you will find a lot of customization and it all works. it's also very familiar to use if you're coming from windows.

4. do your monitors have different refresh rates? that was an issue, I think that got fixed in wayland. x11 will not be your friend. someone correct me on this one if I'm wrong.

5. I stand by what I said in 3, but go ahead and try them in usb live environment and see if you find it okay to use. btw you can install KDE plasma in mint too, you're not married to the DE that your distro ships with.

you are probably going to need to set up a virtualbox and use photoshop in windows, I hear it doesn't work well in wine.

So you like tinkering? Just install Arch and go wild /s

1. Does the distro I pick matter?
   Packages
   When you install a distro it will have repositories of apps that you can easily install and easily keep updated using either the GUI (GNOME Software for GNOME, Discover for KDE) or the package manager in terminal (dnf in Fedora, apt in kubuntu and mint). It's similar to how you install apps on a smartphone.
   The good thing about the apps from the default repository is that they're (in theory) tested to work well with the distro.
   You can also install applications from other sources when necessary.
   Update Frequency and new tech
   Another difference is how new kernel and software you get from the repos.
   The latest Debian Stable runs kernel 6.1 while Fedora just updated to 6.12 and arch has been running 6.12 since december.
   If you're running the newest hardware then the chance of having drivers available automatically increases with a newer kernel.

2. Company-run distros and alternatives:
   In my opinion Ubuntu is the ones doing the most forcing as of now, and even they are angels compared to Microsoft.
   Fedora had discussions about including opt-out Telemetry to aid them getting data to improve the distro. They listened to community feedback and backpedaled that into opt-in metrics:
   https://fedoraproject.org/wiki/Changes/Telemetry
   https://fedoraproject.org/wiki/Changes/Metrics
   Debian and Arch are both examples of distros without enterprise involvement and that have no upstream distro that can affect their releases.
   Map of distros here: https://upload.wikimedia.org/wikipedia/commons/1/1b/Linux_Distribution_Timeline.svg

3. Stability of the distro:
   Of your frontrunners I've only run Fedora but that has been stable and been working well for me for my primary PC. So has Debian which I run on my servers (I have a Debian VM running Portainer for dockers, one for running Jellyfin and a third for Forgejo).

4. Monitor support
   Multi monitor support
   I don't have the desktop space for double monitors personally, but I've heard that KDE 6 (Plasma) handles multi monitor support well.
   HDR
   Should be working since November

• https://9to5linux.com/kde-plasma-6-2-4-re-enables-hdr-mode-for-users-on-nvidia-565-and-linux-6-11

5. Both KDE and GNOME are customizable. KDE is more similar to Windows and I realized that most of my GNOME customizations was to make it more similar to Windows and KDE. I've since switched to KDE and must say I really enjoy having a proper file browser as default. Nautilus (default GNOME file browser) has been simplified to death and caused me to create a script to replace it with nemo.

Nvidia is a whole lot simpler to use than people make it sound like, though I'll stay team red:
https://rpmfusion.org/Howto/NVIDIA#Current_GeForce.2FQuadro.2FTesla
Fedora guide for Nvidia drivers unless you're running a really old card:

sudo dnf update -y # Update your machine and reboot
sudo dnf install akmod-nvidia # Installs the driver
sudo dnf install xorg-x11-drv-nvidia-cuda #optional for cuda/nvdec/nvenc support (required for Davinci Resolve)  

• Gaming including emulation
  First person shooters with kernel intrusive Anticheat won't work in Linux as they expect to spy on a Windows OS.
  Other than that gaming on Linux is really getting there as I'm sure you've realized when using a Steamdeck.
  Outside of Steam you have Heroic Games Launcher, Lutris and Bottles for running windows games on Linux.
  I'm mostly using Lutris but I think Heroic Games launcher is the more popular one.
• Firefox
  Default browser in most distros
• VLC
  Available in most default distro repositories.
• Spotify
  Available as a Flatpak on Flathub, haven't used it myself.
• Discord
  I know people has had some trouble with screen sharing but that the DiscordCanary (think Beta version) solves it.
  https://github.com/flathub/com.discordapp.Discord/issues/380
• Godot
  Can be downloaded as a simple bin file from their own site: https://godotengine.org/download/linux/
  Also available as a Flatpak on Flathub
• Visual Studio
  The closest you get is VSCode.
• Git
  Not a problem.
• Photoshop cs6, audacity, davinci resolve
  Photoshop might be trouble, Audacity and Davinci Resolve should work.
• Misc “Tinkering” (Handbrake, dvd burners/rippers, Really any weird thing I come across that I want to tinker with)
  Handbrake is available as a Flatpak on Flathub, there's dvd burner applications available too.

1). It matters a little bit, but not a ton. A big difference will come down to what package manager comes with a distro, and whether it is a "rolling" distro that gets updates as soon as they come out, or one which withholds updates until after they have some time for bug testing, etc. Given that gaming is one of your primary use cases, I would recommend a rolling distro. If your distro does not come prepackaged with something you can usually install it. Minimalist distros like Arch come with almost nothing pre-installed, not even a desktop environment, so you can be very granular about what gets installed and keep you system lean.

2). Most distros will not have as much in the way of corporate control/privacy concerns. A few like Ubuntu or Fedora are more closely linked with a single company, but most are more community driven and this is not a concern.

3). The advice I always give to people first trying Linux is to go into it with the mindset that you are learning a new skill, as many things are simply done differently to Windows. Most things work fine, but every once in a while, especially when setting something up for the first time, it may require additional configuration steps. Very popular distros like Mint will usually have the most community resources, and you can often find posts or guides of people who have already solved some issue you run into. I would also throw one of the Arch-based distros onto your list: Endeavour OS, which is essentially a pre-configured Arch installation. The Arch wiki is one of the most highly regarded resources in the entire linux community, and even if you are not using an Arch distro, many of the guides on it can be helpful.

4). Generally speaking, my multi-monitor usage with KDE has been seamless. No issues that I can think of. HDR support has only very recently been added, so I am not sure how well it works, but it is improving rapidly.

5). I think Plasma would be a good fit for what you are trying to do. Honestly, it is very customizable, but perfectly usable right out of the box even if you do not want to do anything to it. The layout is very familiar for a Windows user.

I don’t have anything to say that everyone else hasn’t so I’ll just wish you good luck and hope you have an enjoyable experience

Okay, people have said many good things so far, so I won't add much. Simply one thing: take one problem at a time.

By this I rather mean, make your life easier, and only progressively deal with more complicated things. When it comes to distro choice, this would mean picking something with plenty of default installed packages (since you won't necessarily know what to install yourself) — this rules out my beloved openSUSE Tumbleweed as well as the popular Fedora and Debian — something that will play nice with NVidia (Desktop Environments use display managers/servers, the two most common being Wayland and X11; Wayland is better, but unfortunately will really mess up NVidia gaming, so try to stick to X11 for now — you can always switch later!), and, lastly, something with a large community (and by extension a large help forum and wiki).

I never thought I'd hear myself (see myself?) saying this (typing this!?), but Mint checks all those boxes.

I wouldn't recommend staying with Mint for long (though some people claim to enjoy it...), but as a first distro to introduce you to Linux, it really may be the easiest. Using a different DE is already difficult, don't overwhelm yourself from the get-go!

Alright, that ended up being longer than expected. I wish you the best of luck, and a lot of fun on your approaching Journey!

So I don't really have experience with the gaming aspect as I pretty much get what I want from a steamdeck. I think its likely you would want to go with one of those (a gaming setup someone else suggests) or dual boot to have your gaming system and your doing other things setup. Just in case I will mention the one I use called zorin. It is based on ubuntu with gnome and its main claim to fame is its an out of the box distro that tries to emulate windows (other systems to but the paid for version unlocks that. its default is a general windows type experience). Out of the box means it has foss office, video file viewing, audio file listening, image file viewer, browser of course, rdp client, mail client, calendar, contacts, also image,video,audio file creation and editing, optical disk copier/image creator, wine with play on linux so that you can right click a windows executable and run it and such. It does non free software things like nvidia drivers right off the bat. Its great for an install and get going right away type of thing. Its always a bit out of date because its emphasis is stable, just works, get going type of thing. I have a few complaints. Mainly it does not have the windows key, right arrow thing to half screen by default. It could be a stability thing that they don't want to mess with the compiz or whatnot. Then the other thing is I find the software gui interface it have an aweful search for getting more software so either just use apt at the command line or download the .deb installation file which things like various browsers have as a linux option for download and then its really just like adding one to windows or mac. download and run the installation.

Others have already answered your questions, so I'll just drop in my anecdotal experience to moving over my desktop to Linux last year. I tried a few different distros but settled with Fedora KDE edition. It works with everything exotic in my laptop out of the box, except for the gyro that doesn't work with anybody else either. The desktop feels familiar and is easy to customize. I tried to like Gnome and variants but it is really settled on The Gnome Way of doing everything. Fedora is a fresh experience from previous attempts of going full Linux desktop with Ubuntu and even Mint. The GUI for software and package management is neat and includes native packages, flatpak both the fedora builds and mainline. Some minor things are not quite there but I believe that will be the Linux experience forever and I'm okay with it. I recommend to try it.

try a bunch in live usbs and see for yourself

There is no right answer. There are many distros to choose from and each has its pros and cons. My suggestion would be to try a few things in VMs before fully making the jump. Personally I use Mint. It just works and takes a minimal amount of hassle to install and run. If that's a priority to you, I'd suggest checking it out.