It's worth noting that the NTSB report is 20 years old and there should be a lot more data to analyse and perhaps draw some new conclusions from.
Is it just a poor combination of head design and rotor blade manufacture?
If it had been built with a simple teetering head instead of adding the flapping hinges, would that have prevented the extreme levels of flap required to strike the tail?
Hot and Hi
Somebody please tell me. Richard's article is silent about this.
you will just have to use your own judgement - that is what professional pilots do. If you are not sure of the amount of turbulence then don't enter it at Vne - go in slow and test the environment, giving yourself good safety margins and escape routes. You seem happy to be able to identify mild to moderate turbulence so if it starts to feel like the top end of your acceptable range, turn back or land but definitely slow down.
Birdy - didn't mean to patronise, sorry.