I'd like to second Budd's sentiment that training should focus on very simple use of ground, in the beginning. Getting carried away with the ideals you ultimately want in your training is dangerous. I think I wasted time when I should have just been pushing walls/bungee cords. Once you have a simple, clean skill, of course you can build on it.. but cheat yourself out of a good foundation, and whatever you end up with is just fancy elaborations of crap. I don't think anyone here would argue against this-- I just wanted to reiterate.
Regarding the decision-making vs conscious-awareness-of-decision stuff, I think it is reasonably clear that often our conscious minds only infer that decisions are made, and when. That's fine but it is beside the point for the topic of this thread. I agree it is something any martial artist should think about - no matter what method you train-- but it isn't quite the point here, see below.
As it relates to Jiyu Waza, (IMO) Mu Shin is probably the optimal mindset, and calm observation is second.
I agree with that too. But it is beside the point of this topic.
You could look at it this way: "intent" is a part of the motor system that has to do with the way force (input force, or your own muscles' force) is routed through the joints of the body. You can train it and use it either:
1. as something you volitionally use in martial techniques, i.e. NOT using mushin;
2. as something that is used in a way that is constant, rather than contingent on decisions and circumstance. i.e., a way compatible with "mushin."
Originally, I thought the inclusion of the "desire" stuff in the coffee cup demo was an eloquent way to incorporate a bigger picture into the demo. But it isn't the main point-- if you just sit, then relax, then go to reach for the cup BUT INSTEAD abort the reaching action before you have moved at all, that is enough for the main point. Who makes the decision, when, and why are all beside the point. The point is just that the body has a way to tense something inside, which is independent (separable through practice) from the action of the muscles that will subsequently fire in the reaching task. That "something" is ki, it is controlled by intent, and it can be used for something much cooler than how it is used without internal training, when someone grabs coffee the "regular way."