Pdittrich,
good general brief about the subject.
I've never flown a real Helicopter, but I used other simulators and made some attempts with RC Helis. The only conclussion you can get is that: what we have in Il-2 doesn't have anything to do with a real helicopter.
A lot must be done regarding FM and a completely new modelization considering the real forces (which are not all corresponding the ones of a plane) that act over a helicopter.
In our current models, if you turn off the engine, the Heli will slide a lot, like a plane does. Real helicopters without theri main rotor working fell to ground exactly as a stone.
In planes, the lift force is is a result of the thrust. To be in the air, the plane has to be moving forward too. This is not the case of helicopters: lift is only the result of the vertical force the main rotor produces into the blades.
Another hugely different effect if what happens when you move your stick to one of the sides. Again, the plane needs to be moving forward to roll over it, only the thrust made the ailerons to produce the effect we know. Helis can go to side (and most of them backwards too) by just slippipng the stick to one side (or back). It produces an instant effect that doesn't have any correpondence in the planes world.
Perhaps not a very possitive comment: but I don't think that could make any sense "to master" your skills in this evaluation helicopters. They are too apart from reality. If you become a great pilot of these, it will not help you basically at all for a real one.
Code for helicopters that act like an helicopter should be developed. We only have 3D that corresponds to helicopters with some little weird plane behaviour.
Regards,
Pablo