What better for new users to use as a guide for who to trade with than an almost completely opaque trust system that nearly no one understands. Brilliant.
I disagree. Whether or not a user is generally seen as "trusted" is very easy to understand for a new user. The big green or red numbers under their name, with the added "Trade with Extreme Caution" tag, couldn't really be made much clearer or much easier to understand. I don't think I've ever seen a post from someone being confused about that. Whether or not you agree with those numbers is another matter, but they are not difficult to understand.
Once a new user has been around for a while and can start to make up their own mind about who they do and do not trust, and whose ratings they do and do not value, they will want to think about setting up their own trust list. That is when the issue occurs, and it is that which should be made easier and more accessible to the average user, not more complex as in Quickseller's proposal.