There is software that you can run on a Raspberry pi, you can set a second monitor HDMI output to the pi with HDMI input hat and feed your USB peripherals through the pi. It acts as an aim corrector, and also can take hints from the game output that can help show characters through walls, etc. External input devices have nothing to do with your kernel. Cheaters are going to cheat, kernel access is just a way that game makers can say they’re trying to combat them without actually doing anything and exposing your kernel to third-party programs at the same time.

I run Linux, so I didn’t really play any first person shooters that require kernel level access, and even if they were available I wouldn’t install them on my system. I would really see the solution more as something to use as a layer on an immutable distribution instead of trying to give external software full access to the kernel on your system.

Yes, but it’ll also be a full-fledged desktop computer running. KDE and likely arch Linux. Finding a decent desktop with those specs for around $600 is a stretch. Being able to use it as a console is a decent bonus.