Honestly, I've never seen a Fandom Free-for-all survive long. I'll spare you the lecture on good writing, because this is not a place for literature, regardless of how some people choose to write(or try to). 

What I will share is the benefit of my experience, and thus a warning: Trying to please everyone ultimately pleases noone, and wherever chaos (such as a setting with no clear rules or themes) is an option, chaos will thrive; if you make adhering to the setting, following your rules, optional? They won't.