You are explaining your abstractions OK. However, they are simply abstractions. There is no present, there's only relatively present compared to obviously not present. You imagine that something is going on "now" somewhere that is inaccessible to your senses due to speed-of-light and relativistic concerns. However, that's your imagination, that's a set of abstractions that you conjure in your mind. It has no basis in science or sensory phenomena. It's like the Heisenberg Uncertainty Principle. You say something is happening somewhere else "now" on faith. Heisenberg isn't so sure. He says show me, and you can't do that because it's impossible. That's why I say there is no such thing as actual simultaneity. It's a myth.
Well, if you wish to explain them away as abstractions, then I guess you'd rather see the idea of the universe itself as an abstraction, as simply a thought exercise, with no proof of existence.
You have to draw the line somewhere. We could all live in a holographic simulation - hell, the universe could be physically real but at a certain dimension, everything we know might be a holographic projection of data in a particular dimension.
What we know of space and time, and collectively spacetime, is that yes, at a certain level, time is time is time, and that time now is time now elsewhere.
Where it becomes murky due to relativity is observation of simultaneity. But observation is a matter that frankly does not even get considered in your question. Now = now. We are not asking about observation of now, we are talking about now.
There is no universal clock, we've invented that based on our presence and observation. What does exist is a universal scale in time, much like 3D coordinates. Time as we understand it, outside of observation by life, can be represented as an extension to coordinates on a map. However, this map has an added dimension.
It is not at all remotely easy to wrap ones mind around the concept. A 4D construct is nearly impossible to truly understand. And granted, this idea we have of "spacetime" may be entirely wrong, but I feel regardless of what comes to be "true" in relation to the fabric of the universe and whatever dimensional truths it holds, time is going to be a consistent construct at the most fundamental level. Time only gets "confused" by the presence of matter and gravity, otherwise, it is as consistent as the speed of light. In other words, time only gets weird when light gets messed up by gravity.
What we call time here and now is a human construct, based on our interpretation of time within our reality. That reality exists on a solid body, in its gravity well, which itself lives in a larger gravity well that is itself in yet another gravity well... and on and it that goes.
So to define "now", asking if that equals the same now in an entirely different location in the universe, is itself sort of a trick question. Yes and no. Yes in that, at the most fundamental level, if you remove the abstractions created by the varied levels of mass and gravity, the base time is absolutely the same.
But no, in that if we put clocks (which are based on our human perception, which is not the rule but merely an abstraction) in different locations, the "time" measured will be different, in sometimes extraordinary ways. But that is not time, that is a human approximation of time in a way that lets us define our lifestyles.
Certain major elements of Einstein's general relativity and the fundamental level of physics we've understood thus far, have been "proven" in recent efforts. Not that what that data represents is the end of all questions, as it does not preclude other theorized elements from existing as we suspect.
Dark energy, and/or the cosmological constant, have been demonstrated to exist. That does not mean that something spooky is working, just that there is something that we do not know or see is interacting in exactly the same way as Einstein deduced. Which is quite remarkable.
http://phys.org/news/2016-07-biggest-galactic-dark-energy.html
This may not seem to be entirely relevant, but when accepting that dark energy is a factor and deducing that dark matter and dark energy have been very important in shaping the universe, it very much demonstrates that other principles have thus far lined up, and our understanding of spacetime is linked to what we know of the voids in space and the matter and energy dispersed within it.
I won't remotely pretend to understand the mathematics behind all of this - I can hardly wrap my head around m-theory. But Einstein's spacetime theory has held up incredibly well against all odds. And what further science has even added when attaching time to the expanded dimensions in m-theory, helps show that even the basics thus far understood and/or predicted have held up under scrutiny.