Relativity, space, and time

Plowing through The Fabric of the Cosmos, Brian Greene, on Audible. He's just gotten through the logic describing the existence of all of relative space-time and I'm wondering now what the ramifications are of two events being close together in space-time. It's a nuanced paradigm of reality that leads to questions like 'is light the carrier of time.'
Time is warped by travel through space with the sum of travel through space and travel through time being equal to the speed of light.
Therefore photons do not age.

All of space-time exists at once, but not all frames of reference will agree on which events are concurrent.

Although the notion stated that all of space-time, that is all of space and all of time, exists simultaneously is predicated on an infinite span of space-time (infinite space and infinite time) and I'm not sure that's scientifically valid. Perhaps that comes up later.

Anyway, if photons are the only particle (or probability wave) that can travel at the speed of light (which makes the notion of a universe-wide probability wave for any other particle contradictory) then does the photon carry time? Certainly it is the harbinger of events occurring in some time through all the universe (we read the universal news from time past whenever we look to the stars). Eh. My understanding is weak.

Also pondering if the preponderance of matter (vs anti-matter) is any relation to the arrow of time. Just had the thought that if we carry that idea viewing back past the big bang does a universe of anti-matter with a reverse direction of time exist on the other side? Are our creations of anti-matter in the present somehow twisting the probability waves from that other universe and having them collapse into existence in ours? That seems a bit far fetched.

I'm also left wondering if the notion of a superposition of time is a feasible conception. Time can be relative and exist at all values in any give portion of spacetime, the loaf as Greene describes it, but can there be an observer with knowledge of every event as it happens? Obviously there's no gross physical means of doing this. Observation in the quantum sense is by necessity interaction and such observation would be impossible on that kind of scale. What would record the state of the particles making up such a universal observation machine? Unless there's some dimension that allows for interaction-free observation.

Not a physicist. Yet >.>