If I'm inferring the questions right: no, the difference between "pushing the pedals forward" and "pushing the pedals down" is arbitrary and almost irrelevant to providing power. I mean literally "arbitray" because if, for instance, you start power at 1 o'clock and apply it through 160°, and then get on a feet-forward cruiser and start it at 11 o'clock and apply it through 160°, there is no difference in your power stroke. Because of that I'll also answer, No it is not determined by the angles, orientation and proportions of the bike tubes.
How much pressure is on your saddle is a different story, and doesn't much relate to the power stroke. Unless you're standing up and pedaling, in which case the geometry to the saddle is of course irrelevant.
I think maybe there is another question about smoothing out the pedal stroke, "pedaling in circles". With respect to bio-mechanical efficiency and power output, that makes no difference. A person might want to concentrate on "pedaling in circles" for other reasons, but it doesn't really make you faster, allow you to maintain more power, nor improve your endurance. In fact, it's been found to be a cycling myth that elite professionals utilize this more smooth power stroke than recreational enthusiasts (in some cases, it's actually the other way around).
Personally, I don't pay much attention to it except when I'm feeling some fatigue and change up my mechanics just to rest some muscle groups.