I think I am getting there (or somewhere) slowly. I have actually printed a few pages of the manual to highlight.

I am trying to identify what is actually new and better in NX2 and not merely rearranged and now concentrating on the selection control point (SCP). In NX 1.3 we were able to use a 'colour control point' (CCP) within an area limited by eg a lasso marquee. I think the base mask can do something similar to limit the effect of the new SCP and stop the effect bleeding off over a wider area of the image than intended. But the hierarchy of 'overlay selection' 'base mask' and 'paint and fill mask' is taking some unravelling

The 'good thing' (when one masters it) is that you can then use the whole package of enhancements and not just the limited range within the CCPs - which I had abandoned as they tended to show badly in prints even if invisible on screen....

Now for combination of SCP and brushes...