same here. didn't know there are other DEs besides Emacs
this is the maximalism that i come to hackernews to find.
serious question about exwm, how do you deal with a broken .emacs, and what about when you hang emacs?
I would suggest keeping around some versions :) I use git for this very reason locally when I'm futzing with settings, it's immeasurably handy for experimenters and config file junkies.
Same as any other WM (although I don't actually use exwm). Enable ssh for troubleshooting or use boot flags to boot to console.