Some would say that this BBS is a perfect example of undercategorization of content, especially given its size.
Local branches aside, all conversations are crammed into just a handful of categories, most either being General, Issues, or Polls. But most people seem to like it this way!
I sure have seen (and ran) boards that started out with hundreds of very specific categories, but the growth of content didn't follow. Excessive categorization either leads to strict moderation, or to having more discussion on where to move a thread than on its substance.
What I think would work best (perhaps in conjunction with some of the ideas that are slowly being pondered by the "Creative Team" (sorry, folks, FTL is my happy hour)) is a form of decentralized non-hierarchical categorization
like tagging. Let the readers decide with a click of the mouse (or a text box) if something is funny, dramatic, a flame war, or whatever other tags become popular!
Also, a simple one-click 1-5-star rating per thread / post / user would also be far more effective than the current karma system, which is a perfect example of dysfunctional socialism - original thinkers are punished, crusaders who exploit the system benefit.