Is it possible to achieve torque equilibrium in order to fly?
If I understand the problem correctly, there will be a camera attached around the perimeter of the copter, which must have an uninterrupted view.

If the camera just swings around a perimeter, there will be two problems: 


Trim of the device. There are only three rotors. If the device is in a trimmed hover and the camera swings around, the device needs to be re-trimmed rapidly to prevent roll/pitch.
Reaction yaw. The device starts spinning the other way that the camera is swinging.


Best way is to give the camera a fixed place and make the whole device spin, via gimballing the main rotors or using two vertical propellers. A counter-weight to the camera will put the CoG in the centre.