but I feel there has to be a better and more specific way to teach the internal dynamics beyond telling people to do these things and then repeatedly testing how well they do them. If you actually build a methodology to develop these skills, then the tests have value, but tests generally make poor lessons. IMHO
Well, I agree with that. You're basically saying that the ki-development/tanren part of Aikido should be clearer and more quickly functional, it appears, and I'd agree. In a sense, regardless of its shortcomings in practice, the theory of Tohei's approach is just that. However, let me point out, looking back at your initial thesis, that even so-called "external arts" (like, say, Uechi Ryu karate) have their own "tanren" exercises (Sanchin kata) and the only real problem is that the exactly theory and how-to's haven't been shown to most westerners, so the idea of training from the "inside out" could be applied to most external arts, as well.