He's qualified to become DT1 member because there are 10 users trust him, he also met some other requirements e.g. active. But currently he's not in DT because there are more users distrust him than the users that trust him.
Close.. He's not on DT because more DT members have excluded him from their trust list than have included him. If you take a look at the
list of people he is currently trusted vs. distrusted by, you'll see he is trusted by 7 DT members and distrusted by 15 DT members.
I think it's related with retaliation or personal hate feedback, some DT members will give negative feedback to those accounts with trust abuse as the reason.
Yes that's true, sometimes DT members do this, but it shouldn't be done unless there's an explanation provided for how the trust abuse renders the account "high risk" for trading with.