Yo Paine
Well, your respondant "Carson" is to be commended for
civility and decorum at least, without resorting to the usual
tourettes-like "BWAHAHA..." outbursts. :-) But he studiously still
avoids any cogent response to the SHQ 'Litmus Test' of any viable theory
of gravitation. To wit, what very real mechanism and very real FORCE
literally powers the supermassive BH engine of a quasar? What very real
mechanism and FORCE powers the catastrophic inward collapse of a star
when its core fusion shuts off at iron? What very real mechansim and
FORCE contains the Sun's mass against the expansive force of core fusion
thoughout the Sun's stable main sequence?
If your respondant is willing to address this head-on,
then and only then is there any basis for further discourse with him.
But seein' as how you're bent on attempting dialog anyhow, what the
hell. To address one of his points :

1. GR never states that a "bent nothing" is the cause
of gravity.

It states that "bent space-time" is the cause of gravity. When Uncle
Albert kicked out the "aether", something had to
substitute for it. The mathematical abstraction "space-time" became the
surrogate and euphamism for the spatial medium, the very real
'Something' whose existance was suddenly and capriciously denied after
having been a no-brainer from antiquity. "The Math" became the surrogate
for the reality; "The Map" for the territory, "The schematic" for the
radio, "The blueprint" for the building. But this is not to denigrate
the *predictive power* of the math itself, which has proven itself
correct up to now within GR's purview.
The Lorentzian concept of a 'rigid, immobile' "aether"
was kicked out and rightly so. But instead of following the logical
course of further investigating a dynamic, highly mobile Fluid medium
that's compressible/expansible and amenable to ****density
gradients****, the baby was thrown out with the bathwater. That singular
act of pure caprice and fiat, as long as it remains in force, eliminates
doing the necessary Upgrade of GR from its present 'flat' status.

I'm gonna knock off here for brevity, but just for the
hell of it will address some of your respondant's other points later.