Sure -- and I've expounded more or less the same thing elsewhere to friends by email. Wherein the fundamental point is that the propellor is driven by the wheels and is never a turbine at any stage of the run. For the less-than-wind-speed runup, its pitch faces the wrong direction. And for...
I agree with your thought experiment in (2) and (3), so I recommend abandoning scenario (1) because it's unnecessary and no, I don't agree that the sail in it can overcome wheel drag. A sail moving directly downwind can function only as a (horizontal) parachute (i.e., not as an airfoil), and...