This of course assumes it wasn't a SIG Sauer P320. They do seem to be capable of firing on their own. Which is why the rules of firearms are so important.
Edit: Article claims it was a Glock. Unless you've done something unspeakably stupid to a Glock it won't shoot on its own.
That will be depend on the game. For something competitive like CS2 yeah FPS above all for most players. But for more immersive games like Expedition 33 or other "cinematic" games I think most players will play at the highest settings that still give them a stable 60+ fps.