So Frik'in true!! Planes are a totally asymetric situation! If I use right thrust, do I balance it by the geometric center line? Or do I balance it thru the line between the propeller center and the vertical? I only have vertical area on top.... think that doesn't matter.... Do an inverted harrier then an upright... notice a rudder response difference? It makes sense to build'em straight of course... but being anal about .025" of travel difference between sides when you have a 3 horse power engine turning a prop up front, creating a spiral slip stream, and don't forget the Gyroscopic precession!!!... is a waste of effort...... Take care of the big easy things before worrying about the minutia... we call it "Pick the Low Hanging Fruit First"