Well I guess that's kind of what I was getting at. While you could say that a character made in an existing universe isn't self-created, you could also argue that making a character in our own universe wasn't original because they didn't make up humans, or our world's history or social structure. The only difference between that and a fan-character is that our world isn't copyrighted.

Same thing if you use a more cliched fantasy universe and nothing is really original other than the characters, really. There's too much grey to fully distinguish between them for me.

I'm not really sure what you mean by justifying though...? Do you mean when people make a character that's supposedly a canon character's long-lost sibling/childhood friend and lover or something and actually try to justify it being canon? Because I agree that that is outright stupid xD