clutter imo is just a part of trading boards. there's no real way to avoid it. Ebay threads, etc, etc.
Like I said, I'm cool with it, so long as it's effectively moderated. Rules against bumping, etiquette, etc. We'd need some kind of feedback system and all kinds of stuff.
Besides, we're pretty closely affiliated with a lot of other retro gaming type sites (CAG for one), and most of those have forums with a trading board. I'd suggest that if we do one, we look to those as a model on how to operate it.