Is the proper lowering of the arms a significant contributor to maintaining one's inclination to the ground on the downswing through impact? To me, it feels (key word here) like I have the proper amount of spinal flexion deeper into my downswing the better the arms come down, as opposed to say, keeping my arms completely loaded, in which case, the only way I can get to the ball is to extend my spine excessively and tip my head back.
I'm not sure about you're initial question. Hopefully it will be addressed by a better player. If this is relevant, I start my downswing off by dropping my hands slowly at first until I get into the slot(?) before letting my body accelerate them through. If I try to start too fast from the top, I will often top the ball.
Regarding your last sentence: To me, it feels like my head and shoulders are tipping back and my back is arched a bit at impact. Might be wrong, but I'm not sure how else you could keep your head stationary while bringing your hips, weight and hands forward. I seem to make good contact resulting in decent ball flight - at least much of the time.