Posting problematic code for review is already done in Seekers of Perl Wisdom, so the key issue appears to be the private feedback.

I don't really understand the point. Why get private feedback when the feedback can be posted publicly, to help others? There doesn't even have to be a experience issue, because I (and I'm assumin others) tend to upvote questions that illicit good responses.

A place for monks to get honest, open feedback about their code,....Nobody posts here unless they want direct feedback.

This sounds like PerlMonks :) You can even post Anonymously if you like.