I wish to stress the importance of rudders with choppers.
You should deactivate the autorudder coordination to fly them, because in realistic mode, you need for exemple to apply left rudder when increasing collective, and right when you decrease it (depends on helicopters, could be the opposite with some manufacturers, like Aerospatiale a while ago if I'm not mistaken), the stator coordination is not synchrone alone, it needs action from the pilot.
To land those, the best is to get headwind at around 50 knots, and decrease altitude as well as speed smoothly, to avoid ending in hovering, that is hard to keep when in ground effect if you fly realistically with no rudder.
I think if i remember the lessons in FS were not too bad for the basics, now I didn't try the Agusta, forgive me if it's irrelevant.
Now, for the airspeed gauge, until your problem is fixed you will have to monitor it with shift+z

Just keep some speed like Robert said until the very last moment, and be very smooth with the yoke and collective. If you pull it too fast, the chopper will spin.