I like the trader rating idea. Would we be able to rate people for previous sales though? Like, lets say this starts tomorrow (for example). Would I be able to rate someone based off a sale made a month ago? Or even a year ago? And would the seller be able to rate the buyer? Basically saying they didnt have any issues getting their money.
At the same time, it could possibly hurt some sales. Ive seen a few people that sell quite a few items. Say person A, who buys more than they sell, would have a rating of "0" until they eventually sold something. That would probably deter some people away because theres no proof that person could be trusted (even though realistically they can be). It may take a little bit to break the ice, while someone who has sold a few things already continues to gain more and more sales.
Im assuming this rating would be a 0-10 or 0-100 scale. Maybe instead of giving a 0 to someone initially, everyone starts with some kind of "not-sold-anything-yet" status. That would eliminate somebody who sold one item and ripped someone off from having the same trader rating as someone who hasnt sold anything.
Just throwing the idea and my $0.02 out there.