Since the knob on the driver has no detent, it certainly can be difficult to exactly find neutral. You could rig a switch to simply remove power to get it to stop.

I think you'll want the ability to go both forward and reverse, depending on how the camera is set up and what effect you are after.

As I understand it, the 'click' position all the way counterclockwise(?) on the driver is to automatically sweep the servo back and forth, which will be of no use to you.