Hack, I couldn't agree more. Even in aviation, where there is a certification process for both pilots and instructors and a logbook which I can check, the only way to verify proper skill is to go out and fly with the pilot. Sully Sullinberger came to our flight school to rent a Cessna and even he had to go up with one of our instructors. Ok so that's mostly for show but I flew with a FedEx 777 captain and even he went flying with me for an hour.
Now I'm a bit less aprihensive in an airplane than I would be if I were a driving instructor. 1: things happen less quickly. 2: I have a set of flight controls. I'll let a student go pretty far with a mistake before I take the controls. I'm pretty jaded now when students try to kill me. I can totally see how performance driving can be different since you cant really take complete control of the car and things can get out of hand in a hurry. That being said, as a flight instructor, I can relate to almost everything you've mentioned here.
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