Hi jsp,
Yeah, been working on the blog...still posting a bit here and there though
You make a good point regarding the complexity of forces via various levers working in association with each other via rotational or linear aspects. A lot of this works through the increase in power afforded by eccentric contractions in the muscles which produce the greatest force.
I studied a lot of this stuff when I was an athlete and coach in track & field.
There is not a lot of rotation going on in the body unless you stand away from the cue and get a little discus action going, which will bring in the strong pecs and front deltoid and even lats into the equation a bit more. An active hip pivot preceeding the upper body movement will place those muscles into eccentric contraction, allowing them to explode through more powerfully.
This is why timing is so much more important than pure strength. Flicking a coin is a perfect example of the power increase affected by eccentric contractions. Try flicking a coin without the preceeding resistance.
Back to the long lever. If you look at javelin throwers and baseball pitchers in slow-mo, they bend their arm to create an eccentric contraction in the triceps before accellerating and straightening the arm to generate a long lever. A similar effect may be occuring with Busta's drop down technique.
Still, I think the most powerful untapped force in a power break is timing the eccentric contraction of the wrist. Though the muscles are relatively small, they can exert a very strong force if allowed to flex back and contract eccentrically at the very right time.
If you practice a few shots trying to get the flick in the wrist, like how you flick a coin, or click your fingers, you'll find some impressive power increases with minimal effort and hopefully better control.
Just some ideas