One of the main problems I find in analyzing average hitters swings is the they are to top-hand dominate. Meaning they do not make efficient use their lead-side in applying torque at the handle. However, your posts and description of torque indicates this is the type of batter you would hope to develop.
Below is a post I wrote that addresses the issue of top-hand dominance and an exert from it that contains the "4-Prong Tire Wrench" analogy.
"I may be able to explain why being top-hand dominant can not maximize bat speed with the analogy of turning a nut with a 4-prong tire wrench. Let us assume a tire is lying flat on the ground and you were attempting to loosen a nut with the wrench. To apply maximum torque to turn the nut, you would drive your right hand (or top-hand) forward while pulling back equally with the left (or bottom) hand."
South, You stated, "Torque is the result of a force applied to a length around an axis. So if you had the tire wheel example, just pushing down would cause the tire nut to turn" --- Yes, some torque would be applied by just pushing with one hand. However, as I explain in the post below, far greater turning power would occur if the bottom-hand were pulling in the opposite direction with equal force.