This scene is looking wonderful! Have you had a look at this (very simple) Sub Surface Scattering example on the UDN? It would really be nice to see the light scattering in the candle decrease as it gets lower :)
Well, if you really want to enhance the detail of your high polys you'll never want to hand paint your textures directly. You use your occlusion, normal, heightmaps, cavity or vertex color baked from your high polys as a base, then to add some additional fine grain and photorealistic feel, you mix those maps in photoshop…