If you think the Bursh & Palette is drying up, or drying up of content, you shouldn't divide it into special subforums!
If the type of critique is important, you could simply ask for it. You could start the heading of your thread with [CRITIQUE NEEDED] or the like.
Sorry for the following wall of text. Let's just say that I care for this forum.
1. Why do I post my stuff - it's a sort of blog mostly. I'm proud of what I've done, and documenting it is a way to get vibes out of the figurines and projects finished. Any feedback is welcome, and helps me get motivated to post more, but in reality it's the real-life conditions (time), real gaming in my location (time), photography setting (time), and general hobby interest (time) which get me posting or not. Of course if I'm posting to myself alone, that would be a bit depressing. But usually I can foresee what kind and what amount of feedback there will be, and am happy with it. I could keep a blog, but really, posting directly to people who have similar interests and posting on a board that provides good communication and quotation facilities is much more effective, I believe. I just like forums.
2. Why do I comment others' stuff - mostly to give what I would think I would like: attention. Many projects surpass my skills, so I just say I like them and am in awe. Some projects are clearly by beginners or either by elder people who have different aesthetics from mine. There, I can comment on other things than the painting itself. Rarely, I've seen that someone is threading a similar path to mine, and is a couple of steps behind and not knowing where to get next, and then I've wrote lengthy to point out directions I've found useful.
Connected to this, I'm interested in Empire and Empiresque stuff (DoW, Kislev, Halflings, Ogres, the occasional Dwarf, Mordheim) only. If I'd like to see a subforum, it would be "Non-Empire stuff". I don't actually think this would be a good thing, because a) people paint different things, and most B&P threads are "auteur-specific" instead of "setting/army-specific" - and I do like the mixture: it's personal, and good painters can show their skills and give advice by doing many different things with different kind of figures/themes; and b) it would immediately give rise to the question if these other things should be here or under their own respective forums (40K especially) - which would undermine the fine community spirit here.
The community spirit might be the issue, really. W-E already is a rather tight community of oldbeards, and the thinning of new blood is a reality. We might have discussed most issues already, and seen most of each others' figures.
This is typical of any forum of special interests, I've actually done quantitative forum-lifeline studies with RPG forums. There's an initial upswing, and people posting during the first year or two very much define the forum. This oldguard naturally thins up as some of the people move to other hobbies, get their army painted and move on, or just don't see the point of talking the same issues over and over again. And there are always less and less new guard joining in.
It's very rare that a forum sees upswings after the first three or five years. These upswings are connected to a drastic hobby issue (firestorm on another forum or a totally new/shared way of 'doing it'), or one or two posters 'making the forum theirs' by overflooding it with their own content. Each has their good and bad sides, and neither can be facilitated beforehand.
Also, major restructuring of forums is usually counterproductive to participation. Creating new sub-forums or collapsing old sub-forums rarely results into more discussions. I don't know why exactly, but this is a clear trend.
I don't want to sound pessimistic. And there is one way to improve the issue, which you can read from any forum-specific media article: orchestrate activity either by yourself or by a closed group of friends. Orchestrate it! Find out new issues, create topics to them, and orchestrate some participation. Do it even by creating new aliases, however false that might sound. But avoid heat, and moderate tightly. And this can work, it really can draw both old and new people to the forum, and make/help them participate.
On hobby guides:I think the web is overflowing with painting guides, both blogs and videos, and these are also available in printed format is you want them. None of the guides are outright bad, everything has something to say, and most are clear on what level they aim at. The information is there and it's easy to get at if you really want it. So why should we create more of it?
The special Empire problems these days might be:
1) How to get inspired
2) Where to get alternative figures, which
a) fit together with previous GW editions, and/or
b) provide a quality alternative with scale proportions and breadth of options.
The second one is easy to tackle and I would love to see a complied and updated guide!
-Z