You make a lot of good points. To be honest it starts with attracting the right members, which is an inexact science at best.
Forums cultures can be driven with rules and enforcement, a carrot and stick approach for example. For me, I like the fact that members vote with their feet. Yes, site staff do some steering, but it's a bit like a trying to steer a super tanker lol The fact is if the steering sucks members don't like it. Member can also affect the steering of the site, which is partly where the idea of the group boards came from.
Drive by posters, in general regular members manage their own reactions etc, but staff can help in some ways, for example it is possible we could disallow the creation of topics on the critique boards until a certain number of posts is passed. the reason we haven't put that in place is that we felt that would then just flood tha boards with pointless posts aiming simply at quickly increasing post count. believe me, we are open to all ideas on this.
The same goes for people only interested in receiving critique. So far our approach is to yet again let those offering critique to vote with their feet.
Bring together all those ideas, and the concept of keeping drafts within the community, that is partly the idea for the members only board. We could raise the barrier for entry either in post numbers, members of a particular group only (and having applications moderator previewed, perhaps meeting a specific set of criteria, and / or adding a small subscription payment that would help the site to pay for itself and deter simple drive by posters, cost wise that is undecided but I am open to suggestions. It could be a combination of all of those criteria) The member-only boards are so far getting some usage, but I have had little feedback on the board or the suggestion that it be subscription based.
I think we have an excellent community, that is improving (hopefully you agree!), and the direction that it is going in I think will accelerate just how useful the site as a whole is, not just the community. I can say, your thoughtful opinions all really do affect the shape of the site and community to come.
One point I would suggest: When you see a member posting a song for critique and they haven't set up their About Me page, and their Critique preference, please point them at those features and encourage them to do so.
Lastly, to all, Songstuff does need moderators. Members who would like to take a more active role in the shaping of our community and are enthusiastic about what we are trying to achieve. Just saying