We already have a problem with most people not understanding the trust system. The majority of users do not have custom trust lists, and even of those who do, many do not really understand the difference between trust ratings and a custom trust list, or how the various depths work. If anything, we should be looking to make the trust system simpler, not more complex, as your proposal does. Adding in extra options of including people for "ratings only", or for their list and ratings, will only be understood by a few and used by even fewer, while making the barrier to setting your own custom trust list for the first time even higher. Similarly, your various scenarios for working out whether or not to display the "Trade with Extreme Caution" warning are unnecessarily complex.

This is already the case. If you don't agree with a rating, ignore it or exclude the person who left it.