Lose a blade in a 10-blade rotor and you'll probably survive
Maybe, but it's best if they all stay attached.
could a hypothetical 10-blade rotor with the same diameter as a 2-blade rotor create so much more lift that I could slow the rotor RPM down to make it less noisy?
Orlando Helicopters, which later became vertical aviation technologies (purveyors of the hummingbird helicopter based on the S-52) made a 5 or 6 blade S55 which was very quiet.
IFMU