What needs to be careful when Trading? Seeking experience?

Days ago I saw a post on a tracker's forum where someone volunteered to confess to staff that his current account is bought and want staff to ban it and allow him to register a new one. I feel really bad for the guy who traded with him and are about to be implicated.

Also, when I keep seeing so many accounts after accounts being banned here, I can't help but imagine: what were they banned for? Turns out such a high percentage of bad guys that cant be trusted around us here?

This made me, who was already cautious, even more dare not to trade. So, what can we do to keep ourselves as safe as possible trading here?

What can be thought of at the moment is:

• + Choose members registered for more than 1 year
• + Donors or higher level members would be a plus, as they may be more reluctant to lose their account here
• + Feedback seems to be the most reliable indicator.
• - Someone said before we can ask a moderator to help check screenshots of the other member, so their user class and other info can be seen without blur. But if he's an staff, isn't it very easy to create a normal account to show? This seems prove nothing.

Do you have other experience in choosing reliable trading partners or ensure self safety?

Also, are staffs of tracker the only thing we need to be care of? Are there other possibilities? (For example, sometimes I see a member who has collected tooooo many sites that I inevitably wonder if he's a professional reseller that sell invite I sent to him to someone else? (causing me collateral damage?) Sorry for this paranoid.

i check his posts to see if he get invitatiton from mods and exprienced memebers also i never apply for accounts gas and never ga acoounts only invites because account is always risky.