As a suggestion -- on some discussion relating to things mentioned in the essay -- I would highly recommend reading the thread on Shame linked above in the essay. Many people in that thread made some very relevant points -- with lots of insight in my opinion. You can find that thread here:
Remember, according to Omoto-kyo theology, but also according to any other spiritual tradition I know of that seeks to reconcile the subject/object dichotomy, a sense of shame was one of the drives or capacities that marks the spiritual life.
As for the blog entries on "The Three Peaches" -- yes, I would advise reading everything you can. Especially the writings these blog entries are commenting upon (written by Osensei). I feel Osensei's writings on takemusu aiki may make a lot more sense to many more people after they have read this brief summary on Omoto-kyo theology.
As a (perhaps) meaningless comment, if I understand Mr. Amdur's view on ritual correctly, I would have to say that my own view of Aikido as a system of purification and/or as a ritual (i.e. a rite or a technology of the self) is slightly different. Though I must admit it is hard to note if we are saying something similar or something different - as I believe Mr. Amdur was providing the reader with the benefits of joining him in his self-reflections upon reading Osensei's essays, not necessarily a summary of Omoto-kyo theology.
Nevertheless, as a point of personal clarity, in my interpretation, everything comes back to how the various soul-aspects work in conjunction with the divine soul-aspect. In other words, what brings potency (i.e. the capacity to transform us) to the act, any act (be that a rite before a shrine or be that Aikido praxis), is the cultivation of the various virtues and their corresponding sets of functions as they go on to generate the five necessary drives or capacities that mark the spiritual life. Meaning, if one is not cultivating these virtues and/or generating these drives/capacities in their training, in their practice of Aikido, one's Aikido practice is impotent in terms of operating as a technology of the self as laid out within Omoto-kyo theology. In short, the act is not enough. The act alone remains hollow, empty. The engine for all self-transformation, or self-cultivation, etc., in Omoto-kyo is Ichirei-Shikon. This is the center of every practice. It seems very reasonable to assume that it was the same for Osensei.
For me personally, the act is not enough. The act alone is never enough.
Thanks everyone for your kind words and also for making the time and effort to do further thinking, reading, and/or research.