Some heli's are just sensitive. We've had several real life Gazelle pilots test her out and they helped us fine tune the FM to what it is now. What we strive to achieve is realism. So we will continue to work with real Gazelle pilots to tweak the FM to be as realistic as possible. Keep in mind though, the Gazelle is one agile bird.
Will double check this, but the SAS should be on on Hot start. Without it your pretty much controlling everything, and that can be a bit much.