Boris,
This is a good essay and I sense some agreement with the overall direction. The problem with connecting to my own view is one of both perspective and interpretation. You are from more of a mechanical background, so having to fit pieces together, while I come from a more agricultural background, so the dynamic I see is thermodynamics, because I spend most of my time outside and to me understanding physics often just means not getting hurt, so I keep it simple, but effective.
Consider in my essay, I pointed out that space is both infinite and absolute(perfect equilibrium, as in absolute zero). Now consider the two sides of the cosmic convection cycle, of radiation expanding to infinity, or as far as it can go, before fading to neutrality, as mass coalesces into black holes, pulling into stillness. Which are really the eye of the storm and as the energy radiates and jets back out.
So what I try to say is that space is not "physical," in the sense of being defined and thus limited. As infinity and equilibrium are not physical properties. The Big Bang theory tries to argue that space is finite and flexible, but that is like saying zero is still something, because it is a number. No. Nothing is not something. To be physical means something has definition and motion. Like a temperature of absolute zero can only be inferred, not actually measured, because measurement requires a connection with a measuring device and thus some motion. Nothing has no physical properties, because it is not physical, but infinity and equilibrium are not physical, so they need no cause. Yet everything, including all the math and all the numbers, are between zero and infinity. Nothing and everything.
So that I why I think we need to not try to make space physical.
I can understand why people like to think of space as physical, because the very act of thinking is about boundaries and definitions, so it is like seeing beyond thought.
Regards,
John B Merryman