In every template, so it would seem, you have added the name of the default skin in every folder.
In other words, you have stored "@imagePath" as "default". This concept is nice. However, what you seem to have done is hardcoded the "second directory" into ALL the CSS and templates. That folder is "xenforo".
So, lets recap. An image such as a gradient would be found here in the css displayed like this:
Why not store '/xenforo' in the @imagePath variable? So now, if I want to use some of the gradients (which is natural, considering the amount of CSS and HTML there would be needed to edit this), I have to make my skin directories like so:
@imagePath = "MY_SKIN/xenforo"
I mean, this will work, but what is the point of adding in that random xenforo directory? Is there a point to it? Are there blog/cms/etc features coming where this would be needed?
My suggestion is to make the entire image path changeable, not just the first folder. As there is no point for the second one (at least as far as I know).