I don't think this would work. Despite all validation and "trust" what is to stop you from reversing a legitimate transaction? This is the problem with Credit Cards. I can roll out to a any bar strip in the country and spend up a hefty bill, call my credit card company the next day and say all of these transactions were unauthorized without ever seeing any of those vendors. You can't do that with cash...you can't do that with Bitcoin. If you want your transaction reversed, it's up to You and the Receiver. That's it. Not some mediation company who will favor one or the other.