Well, it sounds like a good idea but I think a sticky in the swapmeet section should be good enough.
One of the problems I see is that an impatient buyer pulls out the red card too soon and gets flogged for reasons beyond their control.... or something in that nature.
Didn't they have that in the old setup?
Yes that stuff does happen on one of the forums where I mod the feedback section, takes a little time to get the right story, but in the end its a very very useful tool to have for both seller and buyer.
I don't remember it on the old forum but I could be mistaken