Mark,
When squatting, should the out spreading of the knees occur during the descent or right as you near the hole?
When performing the power clean, during the jump portion, if the bar is "banged" by the thighs during hip/knee extension doesn't this propel the bar away from the body and therefore make it harder to keep near your torso during the shrug phase?
It should occur from the top down, but it is often useful to think about it at the bottom if depth or rebound are your problems.
Not if you learn the clean from the top using the jump. The bar touches your thighs as an artifact of the re-bending of the knee, and the cue to"Bang" your thighs against the bar is useful after it has been learned well enough that the bar is going up strongly already. What actually occurs is that the shrug counters any forward momentum that may be imparted to the bar by the bang against the thighs, and this forward force is minimal due to the fact that the jump is directed upward.