Dave,
My main concern here remains durability of the blade from fatigue failure - i speak from bitter experience about design for fatigue! It can really catch you out where you least expected it.
To work you MUST keep the stresses below the endurance limit, which generally impies low strain (ie movement). Independant root and tip twists the blade nowhere near as much as this concept. Convince me about the reliability of that system first.
Besides, i still don't buy the aerodynamics. You will get stall either side of the zero vel circle, and leakage through it. Ok i know helo rotors stall well above fixed wing due to vortex shedding etc, but i just don't see the aerodynamics working in practice. Besides as the rotor goes around the azimuth, you are asking it to undergo torture as it tries to follow the airflow. I'm sure you have some novel contruction ideas to enable the blade to do this, but the next risk is then blade flexural stability.
I really do just see this concept as carrying too many risks.
Mart