QTR-Quadtone RIP

Hi, I'm new to this. Until now I was using Qimage for color managed
printing and I wasn't getting consistent results in b/w even with
customed profiles. 
So, about QTR please answer the following questions.
_Does QTR make use only of the 2 black inks that the UCinkset has? 
_Which of the 2, both or that depends on the curve being used?
_For the R800 I can choose between QuadR800 and QuadR800-NK7. What 
exactly NK7 stands for and how can I utilize it?
_For the QuadR800 model there are, in the latest nersion, only
UC-EEnhMatte profiles.Can these profiles be used on other matte papers
or not?

Any input would be much appreciated.