To show the high res textures you need to set the viewport to "Realistic" and then go to Views > Show Materials In Viewport As > Realistic Materials with Maps. Have you tried this?
The sculpt is looking nice! Are you planning to go in a cartoony direction or a realistic one? The sculpt suggests realistic but this type of environment would be great in a TF2 or WoW style.
DAMN Rens!! \o/ Did you PAINT that photo-realistic beauty?? That's a lot of love that went in there! If you painted that hair, than that's CRAZY realistic! :O Awesome!!