My personal opinion is that learning to move with ki/kokyu skills is hard to do because it represents (when done fully and correctly) a radical change in the way a body moves on a couple of fronts. So first, IMO, a person has to be shown how to do it with no weapon and the basics have to be ingrained. Once the basics are ingrained in moving with ki/kokyu/hara then it's time to begin to add a little weight and let the newly-developed (developing) ki and kokyu strengths be trained a bit more, then a bit more than that, and so on.
To jump too quickly to "use internal strength" on a too-heavy suburito or in "doing martial applications" is pretty much one of those steps too far, too soon, for obvious reasons. In my experience, when I've met someone who jumped too quickly into heavy suburi or "doing martial applications" the part that suffers is the development of internal strength.
If you think about it, it's the same reason why weight-lifting is admonished against... it's training that is counter-productive to that hard-to-do real change-over into real internal strength. Don't get me wrong, Jon... I'm not admonishing anything you're doing, but simply stating a point of view that I have.
Mike, I agree with you that we need to know what we are doing to begin with... I was talking about weapons as a development tool and maybe I was not clear on the comptetency level in which we engage in suburito training; it is important to have some groundwork laid down before getting in over your head. I think that a advocation of basic understanding of movement prior to intensifying training is a good piece of advice. To me, this would be a separartion between learning the movement and training. I would certainly advocate learning what you are supposed to do before training in that action...
Its interesting also that you bring up trouble with students who jump prematurely into technique... I recently had a conversation of a similar nature and I think there is some solid argument to advocate a stronger awareness training program prior to getting into technique...
Does that make more sense?