There is only one other subforum ("Chronicles") -- which is partially why I think a subforum off of the RP forum would work well. I agree that more forums/subforums tend to promote clutter, but in this case I think it will prove useful in its utility. People might be more inclined to create more character-oriented threads with a specific subforum, and it will make browsing easier.
Searching with tags does work, but people tend to not tag things or put in tags that don't belong, and in the end, in my own experience, it is not as casual-browsing friendly as just having a specific forum for those sorts of threads (plus, search functions are always hit and miss in my experience).
There are enough threads and people interested in a place to look at those threads to warrant it in this case, in my opinion.
Searching with tags does work, but people tend to not tag things or put in tags that don't belong, and in the end, in my own experience, it is not as casual-browsing friendly as just having a specific forum for those sorts of threads (plus, search functions are always hit and miss in my experience).
There are enough threads and people interested in a place to look at those threads to warrant it in this case, in my opinion.