Oh, the drill in which the recovering arm stops above the water, I've tried that. It's difficult. That might be a sign that it will be helpful to master. I'll work on it more.
I routinely raise my recovering arm slowly and sometimes hold it there or return it to the water. That usually messes up the timing of my kick though. If I can coordinate that drill with the kick, I think it would work much nicer.
What I feel as far as balance goes is that my legs sink more than I want them to. It feels like both arms are below chest level at the same time which adds to the imbalance. But then there are times when I feel so flat that the kick loses power. Sometimes I hit it just right and I can feel that I'm moving more easily.
(I'm becoming more interested in working on the backstroke, but I don't have a reasonably good turn to use with it. I haven't mastered the flip turn yet. I haven't even used the flip during regular laps yet. That being the case, I don't work on the stroke much.)