I believe it will throttle the speed to reduce temps and it will do like a normal PC would and shut down in case it goes too high.

Amen

Yes, at the character selection screen once you’ve beaten the campaign you can select skip campaign and it will unlock a couple of waypoints and allow you to play like you’ve beaten the campaign on that toon

I know you are specifically asking for natives, but with the awesome work Valve has put into proton so many games play well with linux now!

Diablo 4! I just can’t put it down!