I don't think there should be return policies. If I could just wait to get my money back, why wouldn't I?
However, I could see the benefit of 2/3 signing keys. The automated escrow could hold the 3rd key and if things don't get resolved between two parties you could (as a last ditch effort) pay them to intermediate and use the third key to resolve the dispute. In that case it would bring third party trust back into the picture.
No, it potentially replaces it with lower fees.
Say I want to buy a cell phone from somebody for .7 btc. I would open a joint escrow requiring me to deposit, let's say, .9 btc and for the second party to deposit .2 btc. When the phone arrives as promised, we both sign off and .9 btc is released to the seller and .2 is released back to me. This makes both parties accountable.
OK, so the phone doesn't arrive as intended. Depending on the condition we must agree who gets what. I'm guessing either party could update the contract...but until both parties agree, no funds are released.
It could be interesting. I'm not sure if it would work better or worse than the third party escrows we have now.