I'm an EE with some experience in driving electric motors, and it looks like you got pretty much all the basics correct. The only thing I'd add, just to clarify a point of interest to us as EV enthusiasts, is that a PMAC (Permanent Magnet AC) motor, like in many of our rides including my Zero SR, is topologically the same as a BLDC (BrushLess DC) motor. In theory, they're driven differently, but the controllers have gotten very smart and are way beyond any trapezoidal/square wave explanations anyhow. Both the BLDC and PMAC motors have permanent magnets on the rotor, with the coils placed on the stator, which are driven with AC waveforms to produce torque. The frequency of the AC waveform depends on motor RPM (from 0 to ~5700 RPM in the case of the Zero SR), and the magnitude (voltage level) of the AC waveform depends on throttle setting -- the more throttle, the more voltage is applied to produce more torque.
I don't much like the "PMAC" label, because in my mind it implies that the motor is more closely related to the cheap, fixed-frequency, plain-ole "AC" induction motors that are in things like your refrigerator, your washing machine, etc. In particular, these motors have very little starting torque compared to a PMAC motor, which has caused a lot of confusion among EV people that know just enough to be dangerous. Our motors have a LOT of torque at 0 rpm.