lol, KABLUI!
Good work on the tutorial though. I didn't want to type that much, so I am glad someone else did
That is just the way that WoW does texture coordinates, and in truth it is the correct way. The method you mentioned doesn't allow scaling like WoW does. The texture coordinates and eprcentages allow the UI to scale the image at will without destroying the layout of the textures.
It may seem advanced, but once you figure out how to do it, trust me, it gets easier. Texture Coordinates are really the way to go in the end anyway, as most modern gaming design uses it, expecially for texture to model mapping procedures...
EQ UI is a bit strange in my opinion now that I am used to the way WoW does it. WoW just feels more "feature rich" so to speak. You can really do more with it than the EQUI would ever allow...