Hey, "guys", thanks for all the good input; I won't really be doing them all justice in this quick post, just a few notes of clarification:
yeah, I'm using dials not drags. That's why I'm mystified. I was thinking there must be some kinematics beyond the inverse and autobalance that I have disabled, and I could see why that might kick in if you drag a part too far, but if you are using the dials, conservatively at that... why?

I loaded a fresh james in a new scene. Auto balance was not enabled, so I just ticked OFF the IK of the 2 legs (since that is what was enabled). Could move forearms without moving up the chain. Good. That tells me there is something goofy going on  in my armor scene, some strange hierarchy entanglement, even though I did not conform james to armor, or vice versa.
The armor is a figure with full body hierarchy. weird.

No, not using hand cameras.

That set-up room approach sounds great, I hope I can get it to work, because it would be the best approach: get rid of useless geometry, get what I want from the forearms/hands. As long as the hands still have the posing dials and are otherwise poseable after the set-up maneuver. Well, actually, even that is not essential. I mean, If I get the grasping right, and that gets "frozen", so to speak, and only left with the basic properties parameters (trans xyz, etc) to move 'em into place, would work. Well, I'm getting ahead of myself, next move is to just try it, duh :)

sincere Thanks! to all