Simple question, is it safe to use? IIRC in Oblivion and Skyrim it leads to major wonkiness, but I read somewhere that Morrowind ERM is safe if you just save-quit-reload once done.

All I want is to change my character's face, nothing else.

IIRC, you will loose all your spells and disease resistances, including Corprus. (these can be added back with the console, unless they are custom spells)
I think you need to make sure you don't have any active Fortify effects, too.