Peter A Goldsbury
To me, talk of a conspiracy / cover-up suggests that someone, Kisshomaru Ueshiba, for example, actually knew all the time that his father's Daito-ryu training was really far, far more important than his connections with Omoto, but he deliberately chose to downplay or suppress the former, in order that people would (erroneously) believe that the latter was more important: in other words, systematic lying took place on a major scale.
I do not believe that such a serious moral lapse can be demonstrated, even from Stanley Pranin's research.
In your post, you mention Daito-ryu and Takeda as the major factor, rather than a major factor (which is what I myself believe). So I think you need to show more evidence than you have done so far.
I think that really is the crux of the matter.
DR is unquestionably the source of Ueshibas power, particularly in light of his peers, under Takeda, demonstrating the same power which was rather singular in the day. He didn't have it before Takeda and it grew under him.
What he did after and whether he got any more physical power that was from outside of that source is speculation without support
The spiritual components are from his own search.
The conspiracy argument can be negated / explained by Kissomaru believing in what he said and what he was told. That makes it innocent. And others ran with it and romantisized things without evidence. There is an interview somewhere in Aikido Journal where he all but apologizes for diminishing the involvement of Takeda in the history, that could be explained by either intent or ignorance.
Another interview (again with Sato acting as a go between for Takeda) outlines a series of questions posed to Ueshiba in a letter from Takeda wherein he asks why Ueshiba was lying about him; about "a house" supposedly given to him, about the fees begin so large etc. Stan offered that Kissomaru had posession of series of letters that he will not divulge to the public.
Then again,Takeda was painted as a man almost without any redeeming qualities by the popular writers so....
Maybe there are no moral lapses on Kissomarus part and he was telling the story as he knew it- of a beloved dad.
So again inconclusive.
In the end I think Ellis covered it-they were trying to forward a new art, who cared?
Thats not a bad stand alone statement to cover the topic. Until you considered what was offered
when it WAS brought up! A passing reference to what Ueshiba has studied for 23 years and gave him a power sword skills unquestionably unusual for the day.