Sorry, didn't quite finish my thought.
My point with the final paragraph was that you promote what needs to be worked on. Tohei, I assume, felt that there was a need for a better understanding of ki in the aikido community. And he therefore taught about ki. That does not mean that he does not pay attention to other points.
When a new person comes in off the street the first thing you tell them is which foot to place where, how each hand moves and all the other strictly mechanical gross motor movements. Once that's understood you start to walk them through some rudimentary understanding of softening to gain power or the use of one point to prevent balance or some such thing. Over time technique can become sloppy due to emphasis on these new ideas. You then revert to stressing posture and the mechanics of the technique.
In my own progress, I do very much the same thing. I focus on one idea for awhile. Eventually I realize I've gotten lax on one of the others. So I return there. In effect, I'm kind of zig-zagging upwards.
The same is true with breath and rhythm. The mechanics of breath that I described are like the "this is where your foot goes, this is where your hand goes" portion of the technique. But if I focus exclusively on that my technique is useless. So I bounce between each.
As one final example, in breathing exercises there is an explanation that Tohei offers for each component. What happens when you try to coordinate an entire class to one person's rhythm following that pattern? Someone invariably breaths at the wrong pace and then can't keep in sync because they don't have enough air. So the objective becomes to find the rhythm you can do, sync it with the rhythm of the person leading the exercise and make it natural.