Can I just get a few things straight here...
You are:
Intending to human-power a 206 main rotor?
... with 7 - 10 degrees of pitch?
Expecting to get this 500lbs of machine off the ground - even to hop?
Well, thinking about it - if you can get a decent rpm (Yes, I know that was your question) and have some sort of mechanism that snaps pitch on the blades very quickly - like a jump-start autogyro - the high inertia in the rotor system might give sufficient lift for a hop. Using the rotors as a flywheel really.
How will you control it if it gets off the ground?
... somewhat more than the main Xmsn is rated for
In my day, the 206 xmsn was rated at 317hp, which equated to 100% Tq. regardless of engine installed. Originally the max rated output of a 250-C18. - I think.