it's cool to see you guys taking an active role in the forum community. something that a lot of game developers fail miserably at.
i'm a mod at a couple of forums, one of which is sarcasticgamer.com (feel free to remove that if it's not allowed), a pretty well known, and rapidly growing community similar to this one. the thing that helps keep that forum at tidy as possible is they have chosen people they trust to moderate the forums.
mostly things like filtering out the spamming and the baiting and the flaming. disciplinary things are taken very seriously, and i, personally, would rather let the administrators be the ones to drop the hammer.
what i would suggest is to find 3 or 4 people that frequent most of the threads (not just the ones with the name of the band they like) and are active and have a good relationship with you, and make them moderators, giving them the task to keep the forums clean.
i realize that would be quite the job, but i would imagine there are plenty of people out there willing to do the job.
hope that helps and keep up the great work guys!