Helicomparator
After thirty-odd years of watching large helicopters turn final 200 yards behind 757s, Nimrods and other bigjets, I am as frustrated as you at the imposition of the rules which were designed for fixed wing aircraft. However it should be remembered that wake turbulence separation has always been applied between all aircraft on instrument approaches and also between all departing aircraft whether helis or planks.
The major change is that we have to say "Caution wake turbulence. The recommended distance is "x" miles" to every VFR (or visual) helicopter which is following an aircraft of the same or higher wake category. Whether or not you guys follow the recommendation is up to you, but thankfully most of you disregard it.
By the way, none of the rule-writers are able to explain why I can quite legally clear a large helicopter to take-off 100 yards behind another heavily laden helicopter, yet the same two helicopters should be 3nm apart on approach. Do the rotor vortices differ greatly between take off and landing config?
As regards your other point about controllers snapping at you, this was covered in another thread, but it really disappoints me to hear that it is still happening. All I can suggest is that you continue to ask for RW14 etc and if you get a blunt reply, phone the Watch Manager on your return so we can investigate the circumstances.