I like the idea of asking for advice on possible dangerous ideas.
But I'd like to improve on the means: Just inviting arbitrary private communication isn't exactly save. Now OK, LW isn't really arbitrary, but telling 7 people replying on an open post... If the idea really were dangerous... Framing the idea in such a way at least causes curiousity and I had to restrain myself a bit to not immediately jump to the "Send message" button.
A solution could involve trusted rationality counselors. A proxy for this on LW could be contributors with high karma and and high positive rating.
ADDED: I think a wiki page "Rationality counseling" might be a good idea.
I'm interested in discussing this with someone, non-publicly. It's safe to know about personally, but it's not something I'd like people in general to know.
I'm really not sure if there is a protocol for this sort of thing.