Replacing icons reveals some funky cheats used in the default skin, and anticipate my icons not working 100% in all contexts. Some icons are reused a number of places, and if the new icon does not have the same ambiguity as the default one weirdness probably will occur.
A default Opera setup should work nice with this skin, but please make sure that the "Panel Toggle" is active. (Tools - Appearance - Panels - Panel Toggle checbox). Also, I recommend enabling the "Personal Bar" and showing images only (View - Toolbars - Personal Bar, right click on the Personal Bar - Customize - Style - Images only).
Enough talk, click the image to get to the real deal. And please leave a comment. Cheerio!