I hope PFB will reconsider this at some point in the future. I think this is a very good idea.

Really it would only take something like the Suggestion Box, with people posting their draft letters and then other people being able to comment on those posts.

I agree that many people would not use it, but by having everything in one place some people who wouldn't post their own letters might learn something from the discussions about letters that have similar strengths and/or weaknesses to theirs.