Hum...
I still think requests for help will be less answered if they are in a category of their own. They get more "exposure" when mixed in with the rest. A lot less people will see them and therefore answer them.
As for the other two categories, if we do that, we'll have to get really tough on "off topic" subjects. If a skinning question derives in a general discussion, we'll have to be strict to keep the subject directly related to skinning. Otherwise, we'll end up with two general messageboard.
And yes, for those who dislike categories, it would be nice to have the option of viewing the messages of all three forums listed on one page.