Good start on your sim there. I fly RC helicopters and have experience with several PC sims. The first thing I'd like to suggest is that you try and get your flight controls changed for flightstick controls, as having proportional controls is important for getting a better feel of things on the various axis'. This is something you just can't do properly with the mouse. The flight physics model seems a little strange too. Particularly, the effect of gravity seems rather weak, like flying a helicopter on the moon or something. Lastly, the yaw control seemed very slow, though this might just be a symptom of the mouse button control and/or the dual rotor configuration (I prefer a tail rotor configuration myself).
