Time to ponder over some missing links our school Physics text-books did not talk about..

So you know the quintessential force that exerts between two point masses (M1, M2) separated by a distance d. Do you? Lets see..

What is the speed with which the information from mass M1 propagates to M2 while traversing the distance d, so that M1 tells M2 - "Hello, I am here. Now exert the force upon me in this direction." - T seconds? Is T = Infinity or T is finite?

Lets make it easier. Earth is at a distance of 500 light seconds from Sun. It is orbitting the sun. While it was at point A in its orbit, sun has to know of Earth's presence at point A. Does the sun come to know about it instantaneously? Are we saying that gravitational information traverses distances instantaenously and hence faster than electromagnetic wave information?

If yes, then why are we constrained by the speed of light? Why not use gravitational waves to get our information from distant galaxies?

If No, then read further..
So sun comes to know about earth's position some <= 500 seconds. But within that amount of time, the earth has moved and moved a lot to reach a point B. Apparently, in Newtonian model of gravitation, sun's gravitation will not be able to catch up our earth and for that matter any other planet. Yet, our solar system exists. What provides stability to the solar system if gravitational waves take finite time to travel?

Surely there is lot more to Physics and this marvellous universe than our text-books have taught us.