Re: Morihei Ueshiba's Use of the Term "Aiki"
It seems to me that in order to have this discussion, we have to separate out the various hypotheses on the table. As I see it:
0) The null hypothesis--O-Sensei didn't use aiki in any specialized way, but just meant general good budo movement. Any attempt to find a more precise definition in his words is hopeless.
1) The inverse--O-Sensei used aiki to mean blending, matching your partner's attack, leading his momentum, pull when pushed/push when pulled.
2) O-Sensei used the term for a specific set of body skills with known concepts, langauge, and history. But especially post-war, as he looked to popularizing the art, he generalized the word to include peace, love, nonviolence and other good things.
3) O-Sensei used the term for a specific set of body skills and never stopped using it that way. But when he was talking to a general audience, especially after the war, he often spoke metaphorically. So "Aiki is love" should be understoold in the same way as "budo is love"--a metaphorical statement pointing to a larger truth, not intended to be taken literally.
In order to distinguish 2 and 3, we need to know the context and the date of any statement by O-Sensei so we can understand whether he was already looking forward to the popularization of the art, and so we can understand if he was speaking to the general public or to students who knew his method and could understand more technical explanations. For others using the term, we have similar questions--when did they say it, where did they learn about it, and how far along in his own development was the person who taught them the term?
Speaking off the cuff, because I'm travelling and don't have materials with me, I can't think of anything that contradicts 3. But I'm open to hearing otherwise.
Re Ron's video clips, you've made the point that O-Sensei also used momentum, evading, and leading uke. (Though in a lot of those clips there's more than that going on there. Look at how O-Sensei moves his body into uke, even when he appears to be moving uke around himself.)
But a quick scan through the same tape shows O-Sensei not evading at all--look at any of the ikkyu throws for a quick example. So that doesn't really help us figure out how O-Sensei used the term.