It looks good. I don't see any problems.
I would suggest giving humor a separate category. (People who are into humor are usually different people from those non-fiction.)
I can suggest the possibility of creating a few other categories from non-fiction such as "politics" and "business."
That would be a sensible division in a normal library.
However, the kinds of books uploaded here have a different profile.
Much more fiction than non-fiction. And humour might be once a week, if that.
Politics and business is also pretty rare.
And a lot of requesters just put their reqs in any forum. Or if they notice there are several possibilities, they think they should spam their request in every one just in case someone misses it.
Having a more fine grained request system makes sense in theory, but I don't think it would be any more productive. It would certainly be more work for the mods. It gets pretty tedious telling every new poster to read the f***ing rules.