"If you are providing a free service" - free being the operative word here.
In a previous post, Dave clearly tried to promote (vaguely defined) services for (vaguely defined) prices, advertised in a fashion that just reeked of beibg a scam (which is why the post was taken down, I believe). While Dave is still being very weasely, it looks like he wants you to hire him as a community manager. He still does not provide any evidence that he can deliver, so to me it still looks like a "take the money and run" scam, on top of Dave clearly not being good at communication, but all of that is irrelevant - the service they are trying to promote is not going to be free.
We have a forum for hiring / offering paid services, but even if Dave posted there, I'd still heavily suspect him of being a scammer.