Interesting discussion!

One thing I didn't see mentioned is the fact that rudder is the first and last control surface to be effective.

The rudder is the primary control for spin recovery to stop the rotation while down elevator is used to break the stall condition; this is particularly important with aircraft that are dynamically unstable ( not wanting to easily recover from spins). During approach and landing rudder is used to perform both side and forward slips; a primary control in aerobatics. Rudder is used to perform coordinated flight while turning and useful in other flight regimes. Such as sluing gun sights on target during aerial combat or strafing in military applications.

So yes, rudder is far more important than just a control for takeoff and landing ground handling.