Ok, now I'm laughing. We're in real making-stuff-up territory now.
Sure the sun wouldn't be able to exist without gravity, because the matter wouldn't be concentrated in one place... but to say that gravity drives the sun is just ludicrous. What "drives" the sun (in the sense of providing the actual energy) is nuclear fusion. Nuclear fusion is not, repeat not, driven by gravity.
I was sitting on my porch watching the trees sway in a gentle wind and thought to myself "how do those trees get so much water up to their leaves. Then it came to me as I thought that a tree isn't a static object like a rock. It is constantly moving as it sways to and fro. I thought to my school days and the venous return theory based on one way valves in the veins which squirt the blood up to the heart through movement of muscles, not pure pressure. So it dawned on me, why can't trees use the same technique? I love my porch.