I'll second the "Valve's been amazing" comment. The majority of games I play are native, and all but a few of the rest work fine under Proton. Compared to when I started using Linux on the desktop a decade ago, the gaming situation is night and day.
Regarding Fallout 4, though, I played through it using Proton a while ago. As far as I can tell, the mouse thing is just an issue with the game - I found multiple sets of instructions to fix it that assumed you were using Windows.
Regarding Fallout 4, though, I played through it using Proton a while ago. As far as I can tell, the mouse thing is just an issue with the game - I found multiple sets of instructions to fix it that assumed you were using Windows.