Sorry, I'm having a bit of a problem following what you are saying. Do you have some pictures of the camera setups, what works and what gives you trouble?

Also, when you turn, are you using the rudder and coordinating your turns properly? The nextstar doesn't really have excess vertical area, so it is really helped in the turns by proper use of the rudder.

The CG being a bit off to the side shouldn't cause too much trouble unless it's REALLY far out there.

I suspect you are having problems with drag on the one side combined with the drag caused by the ailerons, but I'm not sure. You might try using dual aileron servos and programming in 100% differential, so that the ailerons only move up and not down at all. This should reduce (but not eliminate) issues with something hanging off the bottom of the wing in the airflow. Maybe, I'm not sure.

If you want forward facing video, how about mounting the camera on top of the center of the fuse? direct the exhaust down and to the side, that's what guys here who have forward facing cameras do.