1. If the rudder is on the left, its drag pulls the airplane left, and you throw in a little right rudder to compensate.

2. Ernst rudders are very scale-like in their retract mechanism. All you need is a retract servo to pull a cable.

3. I can get long-winded about this, but if the motor is running, you can turn the plane with the air rudder(and a combination of elevator ant throttle). If the motor is not running...it does not matter.