You may want to put in a nice big warning about More Pet Skins, as trying to play a character which had it active after removing the mod makes the game crash. Honestly, you might be better off removing it from your package to keep people from getting mad (even if you did have a warning and they ignored/didn't read it) and have a "suggested mods" section instead. Including something with a high potential to break peoples characters without at least a warning on your page is probably a bad idea.

I disagree with above. You shouldn't be changing mods mid save.