People who are "accepted" by the owner of the forum should not be in any way promoted and be able to tag other people's profiles.
What matters now is not how many transactions the account is involved in or how many people left a trust rating but if these people are among the privileged.
If you have a better solution please speak up. As it is the current system is the most stable that we have had. Find a plan for forum trust that can't be exploited, or has a lower risk of being exploited, and I'm sure it will be adopted.
Every system can be exploited, just like the current one is. What I'd propose is:
Remove the default trust and make all comments equal. Rate the profile by the number of positive/negative votes.
Allow only 1 vote per account and don't allow newbies and jr. members to leave comments to prevent spam.
What I find strange at the moment are people leaving multiple trust ratings with the same purpose. Why doesn't the staff ban trust spammers or allow only 1 rating per person?
People with multiple accounts would then have greater weight. With your proposed system, you just make 100 accounts, age them, and then become very trusted, and start scamming, or ruin/build up other's trust. That would also give people a free pass to scam newbies and jr.members because they couldn't voice their opinions. As it is now, the trust system is not moderated. Allowing staff to alter trust in any way would leave it completely useless. Staff members could then be influenced to do shady things for others or themselves.
As it is now, the people on the default trust list have a vested interest in the forum. First Theymos, those he picked, and from there those that the 2nd layer has picked, etc. If someone does something wrong with the trust system while on the default trust list, it effects the person above them, discouraging abuse, and encouraging those in a position to add others to the trustlist to think carefully about who they add, and act quickly to fix any situation that comes about. If you don't like the default trust system, individuals can remove the Default Trust list from their own account preferences, and replace it with people they personally trust.