Hovering in the wings,
I feel bad that you feel that you "Never received a straight answer yet" regarding Dave's question about n/rev vibration. Where I come from, a straight answer is one that is true, so I infer from your gripe that you feel nobody has told you the truth yet.
I think you have had two folks ernestly try to describe what occurs when a small number of blades attempt to average out the lift of the machine, while each individually vibrating, circling up-wind near Mach 1 and down-wind near stall. If I can find a better reference for the issue, I will post it. Until then, I suggest that you might look inward when seeking to blame someone for your inability to grasp technical subjects that are beyond your grasp.