Bought Man can't be any of those 4 since SS would have found them when scanned - confirmed by chrmjenkins that Bought Man would have scanned different before being found (see this post). They could be Sneak if not killed. Bought Man has to be Rick, Roric or Twietee.So one more vote and I am dead, so here goes why I voted for Sythas...
Comeagain? was a Traitor. I think he was The Dirk. That leaves The Bought Man. I think the last person we are looking for is hiding among the previously scanned. Remember, The Bought Man is a loyal until found by The Dirk. So I think The Bought Man is either Sythas, Fenris, Ravenvii, or Moyank. I just randomly chose Sythas.