First of all, note that even in a purely "Newtonian" model, such an
observation would not contradict conservation of energy. By hypothesis,
"Dark Energy" generates a gravitational _repulsion_ not an attraction,

Halt it right here. You say generates energy". How?
Did you just find the perpetuum mobile?
Because I my Universe Energy is not created. It only changes shape.
If you start to create energy then the sum of all energies in a closed
system can no longer be constant. It has to go up!


The positive kinetic energy of recession is exactly canceled
by the negative gravitational potential energy of the repulsion exerted by
the "Dark Energy."

If that would be the case then the Universe should be static (as Einstein
had originally assumed). not expanding and most certainly not at an ever
increasing speed. We are talking massive(!) accelleration here my dearest.


Second, you are suffering under the conceptual delusion that velocities are
"absolute," and can be compared across a distance.

So now I'm dellusional, eh? Well it was not me making those claims of
accelleration. That where some theorists and I assume they must have used
some fixpoint to arrive at the "Galaxies will move at the speed of light"
conclusion.

However, in Relativity,
velocities are RELATIVE (hence the name!),

what name? Velocity is velocity and relative is relative. Those two are not
grammatically related.


and in the curved spacetime of
General Relativity, velocities can only be compared =LOCALLY=, not globally,

E-MC^2 - energy = Mass x Speed of Light^2
Thus if you try to accellerate any mass to the speed of light the amount of
energy
required will become infinite (as will the mass).


idea of "velocity at a distance" makes no sense in a curved spacetime.)

Hey, it was not me that brought that idea up. Send your name calling to the
morons who invented the Big Rip theory.

to be in free-fall relative to the Universe, so that by their OWN measurements,
their OWN velocity and energy are =NOT= increasing.

Na, na, na. According to the Big Rip, their entire environment changes.
Not just does the light from the rest of the universe faint out, even the
galaxies
themselves disintegrate as every solar system, and within the solar system
every planet and finally within the planets every rock and atom is
accellerated
to the speed of light into all directions of the space time continuum.

Finally, you falsely assume that it's possible to define a "total energy"
for the Universe;

Well if there is no total energy for a closed system then why do they still
teach that part of Thermodynamics to the kids in school?
You make no sense. If one can not measure the total sum of energies
in a closed system then the claim that those wouldnever change is just
an unproven hypothesis. Or speculation at best.

"preferred reference frame" (and moreover with specific properties that the
Universe doesn't happen to have, namely that it must be static and eternal)

The Universe is most certainly not static, but by definition it must be
eternal.
I mean, where the heck is it supposed to go?

so the "total energy of the Universe" is an undefined quantity in GR.
The Newtonian concept of "total energy" is only meaningful in a small
enough region of spacetime that spacetime may be approximated as "flat."

Last time I checked Newton was not the originator of the Laws of
Thermodynamics.


Sorry, no. General relativity doesn't work that way. In curved spacetime,
relative velocities can only be meaningfully defined =LOCALLY=. It makes
=NO= sense to talk about the relative velocities of points separated by
cosmological distances

Yada, yada, yada. Did you even read my post?
Please read again:
Seriously folks. the "Big Rip" theory states that in the end all matter
will be accelerated to the speed of light, which by itself should make it
become infinite in mass.

Now I demand(!) that you state what points of reference for speed measurement
you accept as valid. If there are none for you that speed itself could not
be measured.
If there are, then read my post and the Big Rip theory again.
Both state clearly that in the end every single atom is supposed to speed
away from its
kind at the speed of light. So you tell me a distance at which velocity
measurements are
allowed and I show you billions of supposed speed record candidates.


Furthermore, the notion of "relativistically variable mass" was abandoned a
long time ago, since it did not in any sense act like a mass,

Not in my cosmological literature it wasn't. And that one is very recently
talking
about the relativistical effects in e.g. magnetic fields of fast rotating
pulsars.


Nowadays, we just talk about energy, and the term "mass" is reserved for
the "proper mass (AKA "rest mass") of an object, which is a RELATIVISTIC
INVARIANT.

Well, I learned in physics that mass is nothing but "frozen" energy and that
was already 20 years ago.


If you mulishly insist on using inapplicable and invalid flat-space

If you mulishly insists on using name calling instead of logical arguments
then I will have to point out that exactly the infinite increase in mass
any object suffers when approaching the speed of light is the reason
travel at light speed is supposed to be impossible.
Now are you on Warp drive here or what?


However, You would be completed wrong-headed and demonstrating your ignorance
should you so insist on invalidly applying this obsolete Newtonian concept
that only approximately applies is small regions of nearly flat spacetime,

You are the only arrogant flat head here Mr.
You obviously didn't even read the Big Rip theory, which is by no means
limited to
you foolish "cosmological distances", whatever that is supposed to mean.
You throw a few cosmo buzz words around as if that is supposed to impress me.

Get yourself educated first before you start yabbing off at other.
All you big word space time curvatures are meaningless as soon as Heisenberg
walks through the door and the Big Rip theory clearly claims infinite
acceleration all the
way to (sub)atomic levels.

You blabbered a lot, but did not properly reply to a single of the issues
here.