yes, this is similar to buying trust ratings basically..
No, this will only stimulate parties to leave feedback (positive or not). This is more fair and more difficult for escrow agent than earning trust when making regular trading... And of course, I will make chargeback only to the address involved in escrow or person must be able to sign a message with it.
imho the only way to truly earn trust is to do good deeds, be trustworthy and just wait for the ratinmgs to come in naturually..