To be honest, I'm not that fond of Discussions. I'd add more relevant categories if no other admins would, but the sheer amount of threads here now makes reorganizing everything tedious unless every thread creator is aware of the new organization and caring enough to move their threads to the more fitting categories.
Update: I've created proper categories, at least the basic ones that should cover everything. Anything not discussing about the game (as in gameplay and related stuff presented in-game) or this wiki belongs to Off-topic.
If anyone else has other category ideas, just let me know. But make sure the reason is justified (for example, the number of threads).