Hi Dave,
I understand how the CV joint works, and how the hub spring works. However, your drawing shows the blade grips to be underslung - the center of the feathering axis is lower than the teetering point of the hub (as in a conventional 2-bladed rotor). CV joint or no, this would mean that (if its a 4-bladed rotor) that the blades parallel to the flapping axis (the ones not flapping) would be moving through an arc when viewed end-on.
The second question also remains - three bladed system: if the blade at the 3:00 position is flapping up, both the other blades (at 7:00 and 11:00 position) would have to be flapping down - this would seem to be in contravention of how flapping works.