Since you have a negative trust people will be unlikely to help you out , getting an escrow or a trusted member to do it for you will make it much easier .
I'm not sure what he want to do with these old addresses. But even if he would use escrow I wouldn't sell my old Bitcoin address to him. He already have negative trust rating for attempt to buy bitcointalk accounts and I believe that he may use our Bitcoin addresses for some bad activities.
I guess so, you must be very careful on that selling accounts of you btc, this may cause you so much in the future.