I'm pretty new as well. Try looking at mounting your hard drives with /etc/fstab. You should try to mount them via UUID and put them in the /mnt folder. I'm using mint cinnamon your mileage might vary. https://wiki.debian.org/fstab
As for the integrated graphics, you might be able to disable them in BIOS.
As for the video drivers I had a lot of trouble as well and ended up having to uninstall a lot of drivers manually to get the right version to stick.
I'd add some fuel injector cleaner. The fuel injectors might be gummed up and when it gets to low rpm it starves the engine of fuel.