I'm not going to say that I know the answer to this, but I'll offer my thought process on these questions, especially with regard to your examples of longer-distance pistol shooting and shooting on the move.
Train the hardest problems you can, as heavily and often as you can. Distance shooting, shooting on the move, shooting tiny targets, shooting and gunhandling really fast. Maintain a little familiarity with easier stuff, but devote the bulk of resources available to harder stuff. The ability to handle easier technical problems may be encompassed in developing the ability to deal with harder technical problems. Although I've had a couple-year divergence lately where I've done lots of stand-and-shoot stuff, I used to practice long-ish distance and shooting on the move at every opportunity I had - the vast majority of my practice at the time. I think that skill development helped me in my subsequent static short-drill shooting.
I may be wrong. This is just my subjective impression of how this works for me.