So you know,..... the next question to be asked (i know too wordy to be answered online) but how is the problem of ukemi to reconciled?
Interesting question. O-Sensei learned aiki from Takeda; in his own development of it he created Aikido. Aikido, all the way back to the 1935 Asahi News demonstration, includes lots of the big ukemi we're familiar with. (Finessing here the question of whether in 1935 O-Sensei was doing Daito-ryu, Aikido, or something intermediate. Whatever he was doing, it included the big ukemi.)
Plus, he said that ukemi softens the joints, or knocks the ki loose in the joints. That's another translation I'd love to see Chris Li look at.
So the guy who knew all about aiki and created Aikido as a vehicle for expressing it didn't see a need to get rid of ukemi. He seemed to think ukemi was important to learning what he was trying to teach.
In our dojo, where our sensei is integrating aiki concepts into everything, ukemi is both feedback to nage and a martial response on the part of uke to keep themselves protected throughout the technique. (Ellis Amdur talks about this in Ukemi from the ground up
--you keep yourself centered and protected until you can't anymore, at which point you roll out.)
So if I'm working with a kohai, and they're putting a technique on by trying to oppose force with muscle, I don't move. I don't freeze up, but I don't let them move me. If they try to deal with force by moving out of the way, or trying to move the point of contact out of the way, I move in on them to demonstrate that they've just opened themselves up. If they move even the littlest bit correctly, I allow myself to be moved by it, trying to remain open and sensitive to their movement so my response is genuine, not forced. Yes, I could shut them down, but that's not the point. This continues up to the point where I either have to lose balance or step out of the technique we're practicing and do something else. At that point, I take the fall.
This lets them practice and gives me practice feeling exactly what they're doing, so I learn where they're tense, where their weight is, and how they're trying to apply force.
Total agreement that this kind of ukemi is not just giving up and falling. At every point, I'm responding only as much as I need to--there's always the possibility of reversing the technique if nage screws up. And you have to maintain zanshin all through the roll and after. (One of Sensei's favorite tricks is, if you try to stand up from a fall too close to him, he just punches you on the way up.)
But from the outside, it doesn't look that different from anybody else's ukemi. It's all in the feeling.