[Southack]

Great questions, but you seem to be getting progressively further and further away from figuring out how to discern the speed of Gravity.

Going back to the basic question of the speed of Gravity, we have so far listed TWO acceptable *potential* answers for the known, repeatable, and observable fact that the planets orbit in planes that are centered upon the actual position of the Sun.

1. The Sun might be *absolutely* motionless,

or

2. Gravity might propagate so fast that the Sun fails to move any significant distance in the time that it takes for Gravity to move from the Sun to the Earth.

[Physicist]

The correct answer is:

3. All motion is relative, fields are defined everywhere, even if they're zero, and the only part of a field that needs to propagate is the changes to the field.