Oh, you just misunderstood what was posted again. The 'main tenet' is that "ways of looking at the world which are related to each other by a coordinate transformation are entirely equivalent from a physical point of view." You don't 'derive geocentrism' from the "main tenet". You derive the equivalence of geocentrism and geokineticism from the "main tenet". Different thing and very difficult for you to understand, apparently.
"...why then was Einstein NOT a geocentrist?"
According to Ellis: "People need to be aware that there is a range of models that could explain the observations,” Ellis argues. “For instance, I can construct you a spherically symmetrical universe with Earth at its center, and you cannot disprove it based on observations.” Ellis has published a paper on this. “You can only exclude it on philosophical grounds. In my view there is absolutely nothing wrong in that. What I want to bring into the open is the fact that we are using philosophical criteria in choosing our models. A lot of cosmology tries to hide that.”
"You think you understand relativity better than him?"
As Ellis documents above, the choice of model is philosophically-based. It is scientifically irrelevant which model you choose as a philosophical preference; the important thing to remember is that, scientifically, geocentrism is equivalent to geokineticism under GR.
" Gravity moves the Earth around the Sun. There is no force that could move the Sun around the Earth while leaving the Earth motionless. Simple physics, no wonder it confounds you so."
Again, "...it is the main tenet of the Einstein theory that any two ways of looking at the world which are related to each other by a coordinate transformation are entirely equivalent from a physical point of view..."?
You would have to claim that gravity is not physical but metaphysical to have a point.
The GourmetDan model: I will not say what force could possibly move the MASSIVE Sun around the tiny Earth, while leaving the Earth motionless (because there isn't one); but either model is equally valid as a coordinate system- and that is good enough for me to embrace Geocentricism as the SUPERIOR model, because either is equally valid as a coordinate system.
Laughable. The scientific model is superior in that it has a FORCE that can ACCOUNT for the motion, not just an “equally valid” coordinate system.