Far as I can recall we have no policy against Fanfiction. As long as it's not adult themed, and then you can still post with some restrictions. You can also use your blog for posting things such as fanfiction. *tries to sleepily remember anything else relevant to the question*
It varies a lot depending on my schedule, unfortunately.
Writing Levels
Advanced
Adaptable
Preferred Character Gender
Primarily Prefer Male
Genres
Psychological horror
Body horror
Supernatural
Giallo
Splatterpunk
Dark fantasy
Historical
Low fantasy
Magipunk
Weird West
Noir
Thriller
Gothic horror
Southern Gothic
Gaslamp fantasy
Cyberpunk
Space saga
Clockpunk
Space Western
Space opera
Paranormal
Modern fantasy
Dieselpunk
Post-Apocalyptic
Crime drama
Medieval fantasy
Yep, fanfiction is totally fine! Make sure to say somewhere what it's from in case people aren't familiar if you want feedback, though. (That's not a rule, just a suggestion. :])
Adult content is fine, but put a warning somewhere on the thread/post (e.g. "18+", "Mature Content", etc.) and/or put the posts containing adult material under spoiler tags.