It seems like a good idea. I understand the freeloaders situation as well. I think that id a haunt is smart enough, they ask in advance, what are you going to do for the haunt in terms of review, show us some legit materials of proof of what you do and so on. (i.e. R.F.R. we leave behind materials for haunts to hand out so people know where to hear the review, we do promotions for the haunts, have press passes on hand, Business Cards and also have talked with events very far before the season go going to arrange visits.
I think a scam review site can be spotted out easily since they hound at the last minute and show up with a ton of people and such and you can pretty tell they are there to get in for free. Descretion is always needed in those situations.
I think that if a haunt feels like too many reviewrs are covering their event and getting nothing in return, they should be smart enough to know when enough is enough.
I like the idea of the site and wish you best of luck with it.
You have your plate full. New video site, reviewer site, those are going to take soem good amout of time to get going.