RE: Pattern planes and full span ailerons.
Turbulence/ disturbed air over the stab.
ie Aileron deflection changes airflow and therefore effectiveness of the rudder and elevator.
The less coupling in a pattern plane the better, so to have the application of one control (aileron) affect another controls power is a negative. Outboard ailerons= more leverage, less airflow disturbance (that matters to us anyway).
Cam