Re: easily accessible videos of Internal Training in Aikido?
Seconding what Marc said.
I've often felt at Ikeda Sensei seminars that he's on to something real, but he's struggling with systematizing it and developing a clear language and set of concepts for teaching it. Like trying to do higher mathematics and having to develop calculus from scratch.
And in my (very brief--thank you, Marc!) exposure to Imaizumi Sensei I had the experience Marc describes. He did something magic--struggled to reproduce it--then suddenly the light bulb went on. Elbow power! 5+5=10! And uke starts nodding and saying, yeah, that's it.
But without the language and concepts that Dan's been teaching, I would have been lost. It's a way to see what was always there, HIPS.