Hi, Brooke! Nice to 'meet' you, in that this is my first post to you. I like this essay, similar to what Larry Niven did for teleportation.

You've independently noticed the need for what tvtropes calls required secondary powers, which might be enlightening. (Be careful; tvtropes really will eat your weekend.)

Good point about load variation; if people can carry more flying than walking, even very slow levitation becomes useful. For that matter, can Andy levitate a car while Bob pushes him at a walking pace to the mechanic? What if they tie a rope to Charlie's motorcycle?

Even at a walking speed there's good reason to fly, assuming that doesn't take any more effort than walking. You can go directly towards your destination unimpeded by obstacles, you must dodge other fliers but not cars, and (inspired by my location's recent rain) you avoid puddles and other ground nuisances.

If it's as easy to float as wanting to, maybe people float around indoors? Akin to dornbeast's comment, fashion could change - what if people stopped thinking they needed shoes?