The essential observation/consequence of General Relativity is that is that everyone (in the absence of non-gravitational interactions) is just floating, or tra

The essential observation/consequence of General Relativity is that is that everyone (in the absence of non-gravitational interactions) is just floating, or travelling in a straight line as-measured-locally. We travel in orbits because space is curved. (“Space-time tells matter how to move; matter tells space-time how to curve.” -- Wheeler) A clock at the center of the Earth runs more slowly than a clock on Earth's surface. The answer to your Lagrange point question is probably indeterminate. The differences in clock rates depend on the relative depths in potential not the magnitude of gravitational force (as measured by anyone).