You have no idea what you're talking about. Characters are copyrightable, and you don't even have to use the exact character to infringe. Just look at Neil Gaiman's copyright case against Todd McFarlane for a recent example.
As far as I know, there have been no broad testing cases for fanfiction, but if there were, any defense would rest upon Fair Use; the fanfiction is clearly in violation of copyright, it would be up to the defendant to prove that 1) they had no profit interest, and 2) they were doing no harm to the IP of the original creator. Even then, they might not be successful in arguing on that vein. The non-profit clause is actually meant to protect non-profits.