I would test the skin shaders under different lighting conditions, the default Poser lighting is really crap.  You will find that one set of lights will work very well and then a different set completely fails to deliver the best results.  I like the concept of controlling various shader settings through parameter dials, that's a novel idea.  Be careful with using Cycles nodes with the PoserSurface, I have seen variability between similar nodes when used that way.