I didn't know all of those categories even existed. I believe my friend is into something like the Fandom you described. She is a character from a graphic novel. Would that be the case?
After reading your explanation, I would say I might feel more comfortable in the PB/Original type of thing. Would those characters be in modern (dare I say normal) times? I doubt I would have the immediate creativity to create non-real worlds.
The Celeb thing, is that where one writes as the actual person and lives via the real person's life? That might require a great deal of research and I am afraid I may poop out before I even started. :/