Peter,
Thanks very much for spending so much time with my essay, and for your questions and comments. I'm glad you agree with the relevance of the topic, and I appreciate the nice things you had to say about the essay.
The first point I'll address is where you said "particularly as the Newtonian description is not quite as I understand it. i.e. I don't think he proposed that light travels at infinite speed from distant events."
That's a good point, and I see I should really clarify what I wrote, which was "in assuming that truly simultaneous events, occurring at the same absolute time, should be described as synchronous in the proper coordinate frames of all inertial observers, Newton's theory is inconsistent with a constant finite speed of light."
This is true enough, but obviously misleading. The difference between the Galilean transformations of Newtonian mechanics and the Lorentz transformations of special relativity is that the factor v/c is zero in the former, which is why Newtonian mechanics is valid at low velocities. Newtonian mechanics would be consistent with the light postulate (constant finite speed of light in all inertial frames) if the speed of light were infinite. That's why I added the word finite in that sentence.
BUT the speed of light isn't infinite, and Newton knew that. His theory describes light as moving at a finite speed that varies between inertial frames of reference.
So, what I said was that Newton's theory is inconsistent with the light postulate--i.e., that there's a constant finite speed of light--because he assumed that truly simultaneous events (in absolute time) should be described as synchronous in inertial frames.
This brings me to that distinction between Newton, Einstein, and what I'm proposing, that you asked for clarification on: Newton assumed absolute simultaneity, motion, etc., and that simultaneous events are described as synchronous in all inertial frames, but allowed the speed of light to vary between reference frames; Einstein rejected absolute simultaneity, motion, etc., retained the assumption that simultaneous events are synchronous (and therefore relative depending on inertial frame), and proposed the light postulate; I'm proposing a rejection of the deep-seated assumption that synchronous events in all reference frames are simultaneous, a resurrection of an ultimate cosmic reference frame (absolute time, space, motion, etc.), away from which any relatively moving system can be described in isolation. This allows for an objective flow of time, as opposed to no flow at all, and contrary to the Machian argument that a Universal frame of rest can never be observed, it actually has!
You then asked whether Einstein ever said "simultaneous events are synchronous in the frame of every [inertial] observer." The relativity of simultaneity is really a hallmark of Einstein's theory. Even if he hadn't said so explicitly, the definition is commonly made that events that occur at the same time in a given reference frame occur simultaneously. But yes, in the first relativity paper, Kinematical Part, section 1 is on the Definition of Simultaneity. There, he writes, e.g., "We have to take into account that all our judgements in which time plays a part are always judgements of *simultaneous events*. If, for instance, I say, "That train arrives here at 7 o'clock," I mean something like this: "The pointing of the small hand of my watch to 7 and the arrival of the train are simultaneous events."
I'm saying this definition of simultaneity needs to be rejected in favour of a Universal definition of simultaneity because that's what cosmological observations indicate, and because that's the only way relativity can actually make sense--and not send us down a rabbit hole where every abstraction is welcome and nothing is/can even be consistent.
Finally, in conclusion, you pointed out that my conclusion fizzles out. I don't disagree. The main point was that without the added structure of an absolute time in relativity, time can't pass; and in fact, whenever it's been denied it's just found a way of sneaking back into the way we think about our theories. The "it from bit" hypothesis is fundamentally inconsistent with this bit of structure--quantum interactions can't occur if there is no prior existence for them to occur in--and that's why I've argued for "bit from it".
I hope that addresses your comments, and helps you to understand the parts a little better that weren't clear to begin with. Please feel free to keep pressing me if anything remains unclear.
By the way, I've only looked at your essay briefly so far, but I really look forward to it. Thanks again, so much, for giving such attention to mine.
Best regards, and best wishes in the contest,
Daryl