I believe in a beginning, but not from a 'central point' for example, the physical universe (+ distant galaxies) all appeared 'at the same time'!
Then you're at least a century out of date, because Einstein showed (and subsequent observations demonstrate that he was correct) that time and space are not universal; That is, there's no such thing as "at the same time" for objects that are in motion relative to one another.
Some distant galaxies seem to be at a developed stage similar to ours, but incredibly, we're seeing an image eons and eons into the past, being that it takes that time for light from that distance to reach us. I dare say, and think you could make a simple logical deduction or rather, a plausible guess from what's known from our current observation. Are the objects going in one direction e.g. going away from us, as an understood by an expanding universe? Well no.. there are stars that are not effected by expansion. i.e. blueshift stars are coming towards us (redshift stars or galaxies are going away). Andromeda for example, I believe is a blueshift galaxy.
Also... a central point of the expansion has never been observed.
Moving clocks run slow. The only way for anything in the universe to happen everywhere "at the same time" would be for everything in the universe to be in the same place at that time. If different things are in different places (and therefore are necessarily accelerating differently to each other) they don't agree on what time it is, nor on how fast time is passing.
GPS depends absolutely upon an understanding of exactly how time varies between different reference frames. It works using Einstein's formulas, and it wouldn't work that way if time were absolute (it would instead require us to use Newton's formulas).
Nothing around here moves fast enough for the non-universality of time [....]
Nothing moves fast enough..
The universe is thought to be more than 92 billion miles in size. Does it mean that 13.5 to 15 billion miles is observable all round, although this is the accepted age? Are we to say then, that the expansion of the universe initially expanded at speeds so much faster than light?
Also wondering that if you can't actually see the very boundaries of the universe, wouldn't it suggest, that you can't really know when the BB and expansion initially occured?
(Apologies for slow response, have to use the phone, a bit tedious)