To assume that your opponent is always within your push hand range is not realistic.
This has nothing to do with push hands. If an opponent is not within range, how I punch is irrelevant. My question was about how someone would punch with every step. It's possible to punch without stepping. A punch with a step will, imo, be more powerful. Turning the body will add more power.
A jab in western boxing is a single straight punch, usually with a step. However, an good boxer can use a double or triple jab, using a single step. Boxers are also taught to use a (left or right) jab - hook combination. But then there's the basic left jab - right cross. Both of these combinations utilize the body at least as much as the legs, Uppercuts, one might argue, depend more on the legs.
Anyway, turning the body is fundamental for a decent hook. And, technically, the front leg pivots, not lands, when a hook is thrown. As I've said, I think the transference of mass to point of impact is the most important thing. Since I study tcc, I'd say that my legs propel my body's mass and I try to transfer that to my hand/leg/whatever.
In terms of punching power, per se, imo the issue is how to generate the most power using the mass that I've got.
"A man is rich when he has time and freewill. How he chooses to invest both will determine the return on his investment."