Gravity dictates the orbits of the planets around the sun. By measuring those orbits, you can calculate the planet's gravity. Here on earth, we have a normal gravitational force.
By the way, the earth's gravitational pull does not "twist" something in orbit - the force it exerts is directly toward the center of the earth, and would be the same whether the earth was rotating or not.
No. the velocity and orbital radius of planets orbiting the Sun has MUCH
more to do with the mass of the Sun. The mass of the planets does create small but detectable shifts in the the orbital trajectories of other planets. If two planets had overlapping apogees and perigees, over a multi-million year period they would probably have occasions when they pass within a few million miles of each other, producing major
shifts in their orbits.