Seen this suggested many times, and every time, it gets my full support. It can save bandwidth, promote RP and give a civilized and regulated way to handle feedback. Flood can be abused, thats where my 'Feedback' thread lies.
In my humble opinion a forum where you can give feedback and improvement suggestions on ones RP is a helpful idea in general. On the one hand the rookies can publish parts of their RP, which they don't feel certail about and let the community give feedback on it.
On the other hand the veterans can request feedback on their RP.
Would definitely be nice. Seems like my feedback threads have been all but lost in the general discussion forum, and I'm sure it works the other way around as well.