You can add stuff to this list if I've forgotten something! You can also claim anything in italics if you'd like to help out (but either put "WIP" next to them if you're working on them, or strike them out if they're done). (If you've claimed something but haven't put anything on the wiki after a couple of months, I'll remove the claim just so someone else can do it if they want.) I can answer any questions you have. :)
Small sects and cults would be cool. Not everyone agrees with the Priesthood?.
There's actually a ton of history that needs to be written up, including plot summaries.
If you like, you can write up any of the places listed above in italics, but please make sure to use the appropriate template.