Hi Jerry, Larry, and Charla,
Great posts and great thread. I have just returned from the Long Island Seminar and had an absolutely fantastic time. I renewed old friendships, made some new ones, tried to work very hard, and learned more than I could possible express.
I can echo each of the comments you all have made above about the particular postures, waist turns, and posture problems. The more I learn, the more I see how many of the simple posture fundamentals I have seriously neglected or misunderstood. All in all I have a much better appreciation for how true conformity to movement principles will show up in a miriad details.
Jerry and Larry, I had similar epiphanies to yours about Fair Lady Works the Shuttles. Over the course of the seminar, I realized I also had premature waist turns (and also sometimes premature rotation of the arms) in the backward weight shifts prior to the 3rd and 4th Brush Knees, in the transitions from Deflect Downward Parry and Punch into Grasp Sparrows Tail, in the Repulse Monkeys, in Step Back to Ride the Tiger, and in the final Deflect Downward Parry and Punch in the Second Paragraph.
Because of all these problems, one of my main takeaways from the seminar is that movements ending in a bow stance appear to have at least four very distinct components: a complete or partial weight shift that allows a foot to be picked up, an unweighted placement of the heel or the toes of that foot, a slight shift of weight onto the foot without a knee bend that flattens the foot and permits one to begin active rooting into the foot by using it for support against the back foot (cheng2), and a further weight shift that is accomplished by pushing with the back leg (deng1) to bend the front knee. While waist and arm rotations can occur during these movements, they often do not seem to span more than one of the four phases or often change directions from one phase to the next.
For instance, between the 3rd and 4th Fair Lady Works the Shuttles, I think there are four distinct waist (and often arm) rotations: one pair to the left as the weight is shifted backward, a further one to the left as the right arm is rotated and pointed to the next corner and the left hand threads (chuan) under the right arm, another one to the right as the left arm is extended in ward off and the left foot is flattened without a left knee bend, and another to the left as the right hand extends to strike/push and the left knee is bent. By way of contrast, in the Repulse Monkeys and in Step Back to Ride the Tiger, there seems to be only one waist rotation that occurs only after the back foot has flattened and has begun actively to root.
A related point I got from all of this is the absolute importance of moving some weight to the forward leg in the Empy Solid Stances (xu shi bu or cat stances). It was very clear to me that this small weight shift was coordinated with the final striking motion of the arms and provided the power, e.g. in Step up and Lift Hands, Play the Guitar/Pipa, and Step up to the Seven Stars. This was also clear in the empty solid stances formed at the end of the jumps in the Saber form, where mere rotation of the waist would seem very weak without the front foot to push against.