As someone who always wants to learn I would be interested in such a forum. Many years ago on another forum, long closed, there was a 'tone' of helpful support. Yes there were comments of admiration when amazing images turned up, but also comments about balance, removing distracting elements, and why didn't you move to the left were also common. Individual posters indicated if they were happy for C&C or not, also if they were happy for others to work on their images. It was reasonably small so perhaps that contributed to the sense of trust and respect that existed. I learnt a lot, although I'm very aware that I could learn much more.
David