With regard to tech crews grading of severity of turbulence.
I was once listening to Bribane departures/approach who had just received a report from one of B.A.'s unflappable gentlemen reporting a slight but noticable level of turbulence at 10 - 15 thou on climb out.
Approach then called aicraft XYZ on descent had he heard the report?
A pause of about a minute then a repeat of the call, still no reply, a further call, no reply, then finally XYZ called, "sorry for the delay, had to find the phones and mike, they ended up behind the seats, and if that BIG B*****D ever calls moderate I'm walking"
It seems to be a matter of pride never to call severe even when the layer of dust that is usually on the floor is level with your eyebrows and the flies are pinned to the ceiling.
The joys of flying the Eastern seaboard of Aus.on a hot summers day