1) Disallow public posting in vendor subforums. It's unnecessary and hurts the communities knowledge of a vendor and/or product. It helps no one if negative issues are brought to light, only to be squashed. If you have a question for a vendor, PM them. If you want to discuss a product, post in the OPEN forum so all can benefit.
2) Absolutely disallow the open advertising of knock-offs. If you aren't willing to put forth any money or effort into R&D, you should not be allowed to profit from the sweat of someone elses brow. Let the product speak for itself, and be prepared to back up that product if you intend to sell it. I don't think vendors should be allowed to post at all about their knock-offs. If you can't afford the "real thing", think about who you are hurting by buying the knock-off. Manufacturers aren't going to make products for a community that doesn't support them.
3) Remove the vendor announcements/classifieds stuff. All I see is the same post in both forums. Just have one.
4) Can't there be some kind of rule about posting the exact same "deals" every day? Or perhaps reducing the number of posts in their vendor thread in an hour. It sucks to open "New Posts" and have an entire page filled.
5) It would be nice if there was an actual review forum. Not the "reviews" link at the top of the page that no one ever clicks.