Hi David. I love thinking about this stuff and I can see that you do too. I wish I had more time for internet stuff-- there is such a rich combination of things that I agree with and disagree with in here. I'm sure there are lots of conversations to be had from this one post. For my part I'll start with just a couple things.
I can see that I think kind of on the same lines as you do, although I definitely think about some things differently, like the definition of ki. But I certainly agree it is a part of us. Body vs mind is tricky, but I'd say there is a tiny line between intent and ki, and they are tied at the hip across that line. The line separates what is body and what is mind.. so although intent and ki in this model are almost 2 sides of one coin, I feel that the ki is decidedly body and the intent is mind. If I understand these things correctly.
One other thing: I thought about the physical ki of the body for a long time. In other words trying to define or understand physiologically. But, what about defining or understanding functionally? In other words, not what is the makeup of ki, but what are the defining functional characteristics? From that point of view (which is NOT in conflict with the majority of what you said about the physiological ki), ki does pass through us. In other words we can "conduct" the ki of heaven and the ki of the earth through our bodies.
And-- regarding ki staying inside us rather than being outside, again I totally agree from the physiological point of view. But functionally, you could say the ki does extend outside-- it's like making the eye see implied line (if that makes any sense).
I don't think now of "accumulating" ki in my body but of cultivating and developing the ki that is there as a part of me.
Budo is farming, right?