I've said multiple times before: DT2 members should require to be included by at least 2 different DT1 members (maybe even 3) in addition to having a net positive number of inclusions.
I must have missed reading those times when you wrote that idea, but nevertheless it's a good one.
Some of the best scam busters are/were on DT2 and not DT1, so I wouldn't want DT2 feedback to be lessened in its weight. But part of me thinks that the trust system is so broken at this point, where we've got good members with bad feedback and vice versa, that the whole thing should be overhauled. I get Vod's point, though I doubt Theymos is likely to share his feelings (but I've been wrong about that before).