Nick,
When applied to today's helicopters; I agree with both of your points
However, when applied to tomorrow's high-speed helicopters(*), these points will no longer be valid, IMO.
Tomorrow's helicopters(*) will incorporate, at a minimum;
~ twin main rotors that are located in the same lateral/vertical plane
~ the Advancing Blade Concept
~ a propulsor that is distinct from the rotors.
These features will overcome the retreating blade stall, and the weight increase is an unfortunate reality that will be necessary for the high forward speed.
(*) 'Tomorrow's helicopters' refers to those craft which utilizes the rotors totally (or primarily) for lift, An example is Sikorsky's X2. It does not refer to tilt-rotors or wing&rotor&propulsor compound helicopters.
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slowrotor,
Dacron fabric maybe too light
Could not find any reference to "geodetic skin"
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Mart,
You got it.
I typed the above offline before reading yours.
Dave