I see your point about the reciprocity, makes sense and I wouldn't worry about the stigma - if your site catches on the stigma will just die faster.

I'm not sure I'd be more receptive to what a friend has to say about someone, but that's generally because what anyone says doesn't matter when the sent/received message ratio is so bad (which is what I tried to fix with the marking idea).

Cool though - will definitely keep following it to see how it goes.