Do you include kundalini in these set of skills. Perhaps even the superset of all these skills?
Sure. At a higher level the practice of taking "essence" from the lower-hara and moving it up the spine to the upper-hara is the same in India, China, and Japan. Same roots.
Is the set of ki, ground path, kokyu, zero-balance by pumping hara and moving tension to equilibrate the body a study in it's own.
Is the division artificial and wishful thinking (i.e. analog to "Aikido is what i want it to be"...True in that it is your opinion, but "False" as in there is not much supporting evidence). Or does it lead ...always ... and inextricably to the deeper esoteric. And the Chinese have nicely answered this with a thundering YES. All things hidden...occult...if you will.
For me; this now goes closer, in a strange way to John's post about the views of the Bible.. One way is a bit ... academic..cold.. easy to handle . If you will. The other gets *waaaay* too close for comfort. Because if that's really true..then..
See, for a long time I thought I could steal the jewels.... Body training for strength, Equalization for balance (zero-point, as I love that term). If there was no line drawn, there'd be no line to cross. Now I am not so sure.
Interestingly enough, Koichi Tohei's learning of Ki things was largely from Tempu Nakamura, who in turn credits his ki abilities/knowledge to an Indian man.
Yet Tohei had no problem understanding that this was the same stuff that Ueshiba was doing while not overtly teaching it and thus Tohei attempted to re-establish "Ki" studies back into Aikido-proper via India. Nice twist, eh?
All of these things are intertwined, yet most westerners doing Asian martial-arts are totally unaware of it because the relationships are not made clear in normal teaching and different styles notoriously use different terms to describe the basic ki/kokyu skills. Shioda mentions that problem of terminology in "Aikido Shugyo":
"Another important point is that kokyu power is not limited to Aikido alone. Originally, it was certainly a part of all Japanese martial arts. While it was referred to by different names, Judo, Karate or any of the various other martial arts all had ways of practising kokyu power. But somewhere along the line it fell into disuse. I believe that therein lies the decline of Japanese martial arts. So in this chapter I would like to discuss kokyu power, the basis of Aikido.
" (p. 76).