Honing a razor requires experience and a feel for when to switch from one grit to another. Anyone starting out will lack this ability so they have two choices, practice and ruin a good blade or get an Eboy special and practice with that until they get the experience necessary. The pyramid is just a starting point in the honing process. For one lacking experience it will enable you to do a pretty good job from the start and once you develop experience you will find its still a good starting point from which to make alterations to suit the needs of each individual blade you work with.

I think that anytime you put your blade to any size grit the name of the game is removing metal. The coarser the grit the faster it will remove it and it will remove it in a coarser fashion. I think you could well develop a bevel with an 8K or even a 12K but it would take forever however you couldn't really polish a blade with a 1K or a 4K you need the 8K or 12K for that. Its kind of like, would you fly cross country in a little cessna at 140 knots or a 737 at 500 knots? Both will get you there but one will take longer. On the other hand if your flying from an point A to point B only 25 miles away its very impractical to take a 737 the cessna would be the way to go.