Re: What to think about this video ("Ueshiba the Archmage?")
OK, here goes. This comes with the disclaimer that if somebody like Chris Li or Mark Abrams disagrees with me, they are probably right, and I am probably wrong.
Those first movements were done with compliant ukes who were helping to demonstrate the principle O-sensei was trying to show. That principle was "owning the space". O-sensei was moving into the space that uke would need to be in if they wanted to be able to launch a decent attack. I don't think uke necessarily had to fall over at that point, but they did so in order to show that they were not in a good situation and they would rather get out of there than try to make a point.
The technique where O-sensei is grabbed morote-dori is actually something that we practice. It is about being able to stay relaxed, particularly through the upper body even if you are grabbed hard and even pushed. He is grounding the force of the attacker and letting it rebound from the ground back into him (not a great explanation, but the best I can do at short notice without being able to do hands on instruction).
The last technique is just a very light irimi-nage. He did a lot of those kinds of light, no-touch techniques in his later years.
I hope that helps.