I would also obtain a separate signed message from the purported account owner to make sure someone is not effectively buying a stolen account. You should also solicit the opinion of theymos or another admin for each transfer prior to facilitating the transaction in order to give them an opportunity to voice concerns about giving the account back to the claimed owner.
You think that they would reply back in a suitable time frame? Most account recoveries aren't being responded to when sent directly to them or posted publicly so I doubt that they would be willing to work with someone offering a service like this. You would probably require permission from theymos on whether this service could be allowed but I don't see why not. I'm just against it because its encouraging paying for ransom.
I don't think a response from theymos should be required to move forward, only an inquiry to theymos to see if he has concerns about the transaction, he may not answer and the transaction may move forward after a day or two without a response, however if he does respond, his advice can be taken into account.