I'm just giving a suggestion just in case this wasn't thought of. I am thinking of an Introduce Yourself Forum where new members can post to get their first few posts out of the way. This would accomplish two things: To relieve the stress new members might face when posting for the first time, and also it would provide some sort of a snapshot of what the member's intentions are.
In addition, I'm proposing a minimum post count where users can send out PMs, maybe set it at 5? That would also potentially reduce the people who jump on the forum with the only intent to sell. I read about one of the members that was sending PMs to other users only to sell their wares. If the posts are gibberish in nature then that could be a tell tale sign the new member doesn't have good intentions.