So Dan, If I'm reading correctly, you are saying "C",( A body ability, that once acquired gives it's practitioner great physical power, making them seem unmovable and strangely forceful.) Is a type of dynamic stability? And this kind of dynamic stability comes from solo training?
If I've gotten that part right, what is this "dynamic stability"? I would describe dynamic stability as a way to quickly and spontaneously align my structure with the ground. Would you say that is a correct or incorrect definition of "dynamic stability"?
Its an incomplete definition, as it doesn't require the use of structure. You can use structure, but it isn't a requirement for aiki. There is a great video from a seminar I attended a few years back which is private that goes over all of this and would be educational.
The notion of stability is very interesting, because it is this stability that makes one appear to have more weight, because they are able to get a greater percentage of their weight into a given movement. Simply put a someone weighing 175lbs who can access 60% of their weight, will feel heavier than 200lbs person who can only put 50% of their weight into a movement. Of course the heavier person has more potential, but can't access it. You have to essentially keep your weight committed straight down no matter what position you are in. This is much more challenging to do, than it sounds.
As for your initial question, there have been studies before with motion capture and other tools for people who are known to have IS. Check back around 2007 or 2008 for discussion of at least one on aikiweb. There are competition videos too, but most people keep them private as they keep most of the how too's for non-public consumption.