Re: Easy ikkyo, painless nikkyo, attacking nikkyo?
Nick I subscribe to that school of thought. Watching those videos, all I could think was "that would be as effective as tickling a cow".
As far as what Mike Signman talks about, I haven't read much from him on the upper cross in a few years but I can say this. I would guess that it is mostly the same thing. I have never disagreed/argued with him on mechanics or his explanations. (We argued over many other issues, but that is beside the point.)
I would assume that he is much farther along in terms of using his back muscles and all of his fascia connections and intentions than I am. In the past, I think he tended to under-estimate what was available in the aikido world. I think we have come to some sort of agreement that there is some good internal training in aikido but it tends to be a slower approach than it could potentially be.
As far as nikkyo. From just an aikido perspective,before I started training with Dan Harden, I could have blocked that nikkyo while jugling 2 balls with the other hand. Since I've been training with Dan Harden, I've learned how to absorb it better and how to use more of my body to blow through them with soft power. And I continue to lear a lot of the slower approach in a much faster way!