Dave, even though we are mostly in agreement on these topics, it still seems to me that there is something about rotational dynamics that you just don't see.
Take your fully rigid rotor, in a hover, and have someone walk underneath and push up on the tail (avoiding the tail rotor, of course.) What happens?
Now take a bicycle wheel, suspend it on a string attached to the axle, attach a weight on the other end of the axle to represent the helicopter, spin it in the horizontal plane and then push up on the weight as far from the axis of rotation as you can. What happens here is what happens to your rigid helicopter when you push up on the tail.
I'll try use words where a picture should be used. The highest pitch at azimuth zero means the blade creates the most force at azimuth zero. That force creates a moment about the center of mass. The entire helicopter already has some angular momentum, once again these angular momenta must be vector summed. Result is the helicopter wants to roll left. The force at azimuth zero continues, so the helicopter wants to continue to roll left.
Another effect starts happening immediately. In the hover, lift and weight were aligned. When the helicopter rolled left, the lift vector is no longer in line with the center of mass. Because of stability considerations, I believe that most, if not all, helicopters have the center of lift above the center of mass. This means that with the helicopter rolled left, the lift vector creates a moment that, if the rotor weren't turning, would roll the helicopter left. Since the helicopter already has angular momentum, the result of the lift vector not acting through the center of mass is the vector sum of all the angular momenta. The helicopter continues to roll left because of the cyclic position, but also starts to pitch forward due to the lift vector's alignment.
It doesn't end here. In the long term, the helicopter does a roll to the left while the vertical axis actually precesses (first example we've discussed yet of true precession). The lift vector of the helicopter starts spinning around an intersecting but non-parallel axis.
Of course, in the longer term, the motion is not easy to discuss here as the "gyroscope" will topple.
My point is that when you make everything unearthly rigid, you have turned the helicopter into a gyroscope. Relative RPM, mass or anything else don't matter. I could make a piece of paper that rotates once every millenium act like a gyroscope.
Matthew.