Today I spent a couple hours at Churchill school's skate park.
I can finally kickturn 180 degrees. It turns out this is quite a bit easier in a bowl than on flat ground; on flat ground there is too much of a temptation to overemphasize the wheelie. In a bowl I could ignore all I had been previously told about starting with my shoulder and following with my hips, and instead take some new advice about keeping shoulders, hips, and skateboard always lined up.
I also got down the basics of pumping, but did not get the timing correct enough to reliably gain height. At least I can go forwards and backwards over flow now.
By the way, pumping badly is a lot of exercise. Each time you skate up or down a curved side of the bowl you stand up from squatting. This means that for each U-shape you make you are standing up from a squat four times, and that happens every few seconds. Until I learn better timing so I can be using my energy efficiently, this is exhausting to practice!
I wrote earlier about carefully choosing to not care if I ever do well with skateboarding. This is still true; it is nice to be able to do more things on a skateboard, but the ability to do more has yet to make spending time on a skateboard more fun than it intrinsically is already.