You can adjust the dpi setting in winecfg to fix the font size, but in recent beta versions of proton I find it necessary to set it back to the default (and restart wine) to actually play the game.

There was one fairly popular fo4 mod that didn't work for me, but the only skyrim one I found that seemed to have a problem with linux was nemesis, and that has now been replaced with pandora. All the other thousand or so mods I tried (currently using 600 or so) seem to work about as well as they do for anyone else.