If you using A7 , you should use Lite-c not C.

Because as far as i know the texture is posistioned based on the posistion of the block, therefore if you move it the texture will move, all you need to do is change it's posistion in WED.

Also models allow greater levels of detail, and render faster as far as i know .

And yes , the textures have to be with certain size restrictions, there is a tutoial for gamestudio which explains this.