I think that the biggest parts of learning to shoot are finding/manipulating light (which doesn't necessarily fit in this discussion) and learning to see the world through your camera.
I completely agree -- and that's exactly
why I think zooms are so much better than primes for beginning students.
With a zoom, composition is a matter of finding the location where you've got the perspective you want and then turning the ring until your subject is framed the way you want. It's very intuitive and easy.
With a prime, you've instead got to start making compromises between perspective and framing, and you might have to switch lenses and start cropping to get what you want. And all that additional time and attention spent learning how to compose with a prime could be much better spent on learning about light.
Similarly, I'd encourage students to learn how to drive in an automatic transmission car. Might a professional driver be able to get something extra out of a manual transmission car? Sure, of course. But what students need to learn isn't speed shifting, but situational awareness and right-of-way. Having the additional confusion of all these levers and pedals takes away from what's important.
Once you've mastered that which is important, then
it's time to start adding on the advanced techniques. But anything you can do to simplify up front is an advantage.
Indeed, I'd start students in green square mode. The first lessons would be on composition (no waist-up portraits in landscape orientation with the head centered in the frame!) and quickly add in light. Only later would I introduce Av and Tv modes, finally full manual, and I'd only mention manual focus late in the game as part of a discussion of the autofocus system. Indeed, I'd certainly spend time in the digital darkroom before discussing manual focus.
Many educators make the mistrake of making their students learn by reenacting the history of the field, keeping them from the modern methods until they've mastered the primitive. This is counter-productive! Make full use of all modern advancements to teach the most fundamental concepts. If there's a crutch that'll let students learn something important without having to claw their way to it, use the crutch! Then, when they understand the important parts, show them how to start dropping the crutches.