Not that Wikipedia is the ultimate authority on anything, some people might find it interesting to read this extensive entry on the history of Japanese Soto Zen. This falls under the general rubric of waking up from storybook zen and acknowledging a more realistic picture of what actually happened - in the past. So many Zen books paint a very simplistic and rosy portrait on the Zen tradition based on the stories of famous teachers. It seems like you are reading history, but it is hagiography, mythology, and has as much to do with what actually happened as Disneyland has do with America. These simple tales might be inspirational - they were to me - but it is such a child-like view.
Kennett knew very little of Soto Zen history. Not her fault. Her few Japanese teachers shared with her a romantic and simple tale of Dogen and Keizan and little else. They wanted to promote Soto to Western audiences by getting some Dogen translated and certainly by avoiding any shadows or dissonance. So all we heard about at Shasta - at least when i was there - were the sanitized histories of Dogen, a little about Keizan, and a few words about Manzan - because there was one piece in the transmission papers that had his name on it - and beyond that, nada. Nothing. And when that happens, our minds fill in the blanks with romantic assumptions of perfect lineages, harmony, enlightened sages, and so on. We assume a kind of idyllic realm with no disagreements or problems or personalities or shadows. Fantasyland. The reality is far more complex and bumpy.
We might think that the Soto Zen past is irrelevant to what went on at Shasta and with Kennett. That is a question worth exploring. I think it is relevant, because many distortions and assumptions and beliefs are transmitted - subtly and grossly - and often in hidden and unconscious ways - and they can be seen clearly when you read a more adult history of the way Zen was actually lived in daily life, in the actions and reactions of players - not as romantic mythology. for some folks, this is way too much information - i get that. In reading the wikipedia entry though, one thing jumped out at me that relates to what is being discussed right now on this forum. In another section, there is a conversation about "mudras" and the practice of JinShin at the Abbey and "magic" or "energy" - and you can see that soon after Dogen died, magical elements started coming into Soto - incantations and prayers. Later we see how Zen was supposed to magically protect the Emperor and Japan, and in the Tokugawa period, healing rituals were common at Soto temples. So this JinShin issue is actually an old story, a common pattern that you can find in many spiritual groups and sects - in Japan and elsewhere. The past is a kind of mirror of the present. These show patterns of human behavior, of group mind, of the need for so many people to create certain kinds of religions, rituals and authorities - and the fear of impermanence, old age, disease and death - and the demand that religion save us from these - through ritual or magic or prayer. Useful to see and know how this works - rather than simply getting seduced and enchanted by a current version of this common dance.
So here is the short version of Soto history - http://en.wikipedia.org/wiki/S%C5%8Dt%C5%8D
Now in other parts of the Reading Corner, i have posted many references to entire books on Soto history - so if really want to look into that mirror, lots to read