Oh I have another one! (Hopefully you don't take this as bad criticism because that is not the way I mean it :))
On the homepage, there's this enormous "post a new article" box, while 99% of the times I just want to read and see where I can contribute. I think most people usually tend to read first (especially regular visitors). Maybe it would be an idea to make that form hidden by default and slide down or something when you click a "post new article" button? And if possible, place the subforum/section selection section (yay what a name) a bit more to the top (unfortunately the ad is there, and I don't want to say "remove the ad", because you might need it there, but it's just a thought!) - that would help people get to where they want to go faster.