Correct me if I am wrong but as far as I know mods don't overwrite eachother or game files. So, you cannot "fuck up installation of any mod" to the point you have to "reinstall" the game.
It is just a simple drag & drop. It cannot get any more noob friendly than that.
Yes, but that is for people who bought the game and this is a piracy forum. Do you know what happens when people update their mods but not their game? They come here and say "help, why is my game crashing" and attach a photo of their computer's screen they took with their phone.