A 2-of-3 multisig escrow address with a hypothetical malicious escrow agent could conspire with one of the parties of the transaction to steal the coin in the escrow address.
I am not saying the OP is acting maliciously, however, based on his current reputation, it would be difficult for an experienced forum member to use the OP as an escrow agent.
Here is my idea -
OP can have two trusted user from this forum. Both these users will hold a key each and OP will have another key. If this is a 2/3 MultiSig then OP can not move the fund without another signature from one of these two users. For every transaction he needs one of them.
Obviously OP and other two users will need to be public (not necessarily to have their personal information in public) about their involvement in the project, and they will negotiate how much they want from the business.
I don't see why the two "trusted" forum members would be willing to participate in this setup. If the OP turns out to be a scammer, their reputations would suffer, and they will have to perform work for less money than if they were offering escrow services on their own.
I also feel like this would be something that might allow someone to accumulate trust ratings when they had no opportunity to steal from any other user, and played a small role in the transaction.