Guys, the developers of FFXIV studied The Elder Scrolls 4: Oblivion to help them in the development of the MMORPG. This tells me that they are going to take a different approach to how textures are mapped onto meshes. Go study the .NIF format, and pick up NIFskope, which is a program that lets you examine meshes in that format.
When you examine it, you will notice that the entire model is actually not in one single continuous model but divided up into different meshes. These different meshes are tagged with different values that will determine how that particular part of the model will appear in the game.
Example: You have a Corsair's Fedora (hat with a big feather) in FFXIV. If .DAT models were compatible with NIFskope, we would be able to see that the hat and the feather are separate meshes with their own set of values that determine how they appear. For instance, the hat may have a texture file determining its appearance, and is tinted by the RGB values in the mesh component. Same goes for the hat.
By applying this method of constructing models and meshes in the game engine, you are offered with nearly infinite combinations of colors and textures that can be assigned to a given mesh. Which means in character modding in FFXIV, the game is likely going to have its meshes reference to a body texture for the model meshes that have exposed skin segments.
It isn't very easy to explain here in text, so I would strongly recommend reinstalling your Elder Scrolls 4: Oblivion copy, hitting up TESNexus.com for the mods and mod tools (TES Construction Tools, Wyre Bash (Python-based tool for save games and mod lists), Oblivion Mod Manager, NifSkope, and finally, custom mods. If you want to go the short way without installing oblivion, you can just download the mods from TESNexus and open the files with NifSkope without ever having to use Oblivion. Just requires pointing NifSkope's directory to the right folder where your mods' files are installed to so it displays correctly.
I might post a thread here later on about this so everyone understands how current-gen and next-gen modeling and meshing is done in the industry. If anyone wants me to do that, just send me a PM with an affirmation that you want to see how it's done!