On the hydraulics off point, page 4-11 of the POH says:
"Hydraulic system failure may be simulated using the cyclic-mounted hydraulic switch. CAUTION: To avoid overcontrolling, relax force on cyclic and collective before switching hydaulics from off to on."
During my hydraulics off training, it did not bump me when the switch was flicked back on. All you have to do is to hold the cyclic and collective with a stable grip, maintain airspeed but do not chase attitude.
raven2, in a partial failure due to pump cavitation, could I suggest turning hydraulics off and continue to fly with an airspeed at the bottom of the power curve ? That's what one would do if it happened in (say) a Squirrel where control problems after hydraulics failure can easily kill you.
When landing, never try to hover - always use a bit of forward speed and do a run-on at (say) not above 35 knots in an R44.