If a blade is thrown on a two blade, bend over and kiss your rear bye bye.
What would happen if you had a 4, 5, or even 6 blade?Would you still be able
to autorotate?

The only thing I've ever heard about a survivable "blade loss incident" was on
an early autogiro (Pitcairn, I think) The test pilot lost one of the four main
rotorblades. The story has it that the opposing blade departed soon after the
first and he was able to sucessfully land.
I also remember that he never flew again.

Tom