I had a Merc outboard on my first Commander quite a few years ago. I remember the throttle arm was a problem. The arm would only go up or forward. There was no room for it to go forward and I couldnt close the hatch. I had to unbolt the arm, stick the arm through the opening from the lazarette to the cockpit, and retighten the arm. Then I could only swivel the engine in one direction. Not so good.

Boats generally back up to port because of the direction the prop turns.

I swivel the engine so the prop is on the starboard side to compensate while backing.

I always got confused as to which way to point the rudder while backing. I finally decided the rudder has little effect anyway since it is in front of the prop of the outboard. I just try to keep the rudder straight. Not so easy because when you start to back up the rudder wants to slam hard over because of the force of the water on it.