But I do have a question for you- I was wondering why you suggest that there is a need to feel the load you are supporting in the dantien. I may have misinterpreted what you are saying, but your post seems to suggest a hierarchy of desirable load-bearing structures, with feet being the most basic, then kua as more advanced, then dantien. I always thought of dantien as more of a focal point for initiating movement that was primarily supported/driven by the ground, via the feet.
I do understand that you want to support your arms with your midsection, to shift away local muscle use in the arms themselves. But I have trouble seeing the dantien as a load-bearing structure that is not itself supported by another, lower, load bearing structure. Of course, I am still in the early learning stages of this, too, and may be conceptually limited as much as physically, accordingly.
To be honest I am not sure if there is a hierarchy, I do know it is relatively easy to feel pressure in one's foot as a foot in the door kind of thing. Now I know in solo training I can get the weight of my arms in various positions concentrated in the dantien area. Likewise I can "pull" the arms a few inches with the middle. Its when I do some of the two person stuff where I do not feel it concentrated there, instead more in the kua.
Given the amount of dantien development we see in some CMA practicioners, I would assume that the tanden/dantien is more than just a manipulator, that it must be an additive. Afterall we hear stuff about bringing the middle on out to the hands.