Ellis, your post inspires a multiple questions and thoughts, but before you get me too far off track, I would like to comment on a couple of things
It is very unfortunate that some practice reduction when it comes to Ueshiba. "Well, his spiritual practices were all just his odd language for internal training," or "internal training? No way. He was a 'spiritual' man!" Didn't someone say that the secret of aiki is in in-yo? So, when it comes to Ueshiba,
this is one more dichotomy that needs to be taken into account. Not either-or. Not even both-and. For Ueshiba, it was "both-either-and-or"
If it is the case that aikido is "both-either-and-or", then it is like saying "aiki = anything that Ueshiba did that was frigging awesome! Oh yeah, and some awesome stuff that other people did too. But not all of it. Or it might be." If that is the closest agreement AW can reach on what aiki is, it seems like it might be better to not use it. At least if we don't want train wrecks.
It is also probably true that Ueshiba began to believe that without the spiritual practices, the physical skills could not be developed. I have two reasons for saying this:
1. His outrage when Tohei demonstrated ki tricks after a night of debauchery - per Tohei's account
What this says to me, if this is truly what happened, is that Ueshiba was wrong in his assessment of the mechanisms for ki tricks.
These are just some thoughts that quickly came to mind, however. I may regret posting this after I think about it some more.