You could only control pitch and roll, but not yaw, since you have only two axis on your mouse.
Yes, but you can compensate with Autorudder, and it would be better than nothing, sure better than keyboard.
Many many years ago I used to play with a pretty good (for the times) helicopter simulator, and mouse was working very well as cyclic, it had an analog response, enough to "pilot" pretty good even the Osprey.
[ame="http://en.wikipedia.org/wiki/LHX_Attack_Chopper"]http://en.wikipedia.org/wiki/LHX_Attack_Chopper[/ame]
For Orbiter, as mouse is still massively used for vessel panel controls, there should be the possibility to enable this feature "on the fly", with a hotkey.
I think this could be a a precious add-on for every vessel, unvaluable during landing.
---------- Post added at 11:13 ---------- Previous post was at 11:08 ----------
There's a utility that just might do the trick. It's called Mouse Raider. It converts mouse movements to keystrokes. Originally designed for use with the old Tomb Raider games, but it might just work for Orbiter. Haven't tested it though.
You can get it here;
http://mouseraider.homepage.t-online.de/
The problem is that keystrokes triggered by mouse are not very useful during landing, in that case you can use simply the keyboard.
What is needed is an analog control.