Ref your questions Sam:
Q. Does it do the same thing if set to defrost..
A. Yes, will run longer in the cycle but eventually shutsdown
Q. Can it be restarted immediately?
A. Yes, I can hit the start button and the cycle replicates as many
times as I restart-ie runs 40 seconds and shutsdown
Q. How is the behavior different than if the STOP button was pressed
A. No difference
Q. Isn't the fan simply on the AC line so how would its speed change?
A. Looks like an AC fan--speeds up only on first cycle--otherwise runs
at top speed. Blade turns freely--no obstructions--low ohms on the
coil--can sub another fan from a different brand if appropiate--your
thoughts

Sam--appreciate your help--thanks