Lu,
I flew the 214B from 78 to 86 in the Sultan of Oman's Air Force.
We suffered the same compressor stall problem, which we 'solved' by an engine wash/bleed band setting check, every day. This still didn't prevent a stall leading to a T/R drive shaft snapping as one of our guys was lifting a sling load. The only saving grace was the inertia in the M/R system allowed him to pickle the load, close the throttle and move a few yards before landing without further mishap!!
We also suffered from 'Nodal Beam Bounce', occasionally the airframe underwent an 'anti-harmonic' with the beam! That was interesting too!
As far as MMH/Fh ratio, ours was high, in fact, at one stage we were known as the 'Static Display Team', with a motto of 'The Sky Shall Not Have Them'
Still, I found it a good beast, and once you'd spent a few days balancing the system, it was the smoothest heli by far.
Maybe now you should be asking if Bell got it right with the 214ST??