1 and 2 is doable using the current system:
Upon receiving some funds you can create an temporary address/private key pair, send the funds to this new address, and use the generated private key to generate the two outgoing transactions. Now store both transactions and throw away the temporary private key.
That way the original address does not vanish and so no coins will be lost.
Nice, didn't think of that.
Are there any escrow services that use this method? If not, there should be!
Agreed. Maybe we should contact Btcrow, and suggest it to them? (I don't think anyone's using it yet.)
I'm taking this proposal as an idea to possibly working on. The only thing pop me in mind is, Is this method won't be to hard for the average user ? I wanna keep every escrowed transactions easy for everyone.