All the evidence points to an expanding Universe. There is no BBT without expansion.
You're entitled to this opinion especially since it isn't a question science can answer.
It is based upon what we see after things were created, so only from some point on or after the beginning (t=0) does this law, and ALL the others, take effect. The creation included the stuff needed to make it all work, essentially, in a near-perfect (ie finely-tuned) way.
"Empty space"
outside of space demonstrates how confusing metaphysics can get.
Agreed. I think most are just referring to a likely scenario over, say, the next 20 billion years. The acceleration of spacetime argues this point. But we don't know what DE is, so how do we know it, or something related, won't do something funky in, say, 50 billion years?
Right, the BBT argues for an isotropic and homogenous universe (cosmological principle).
How do we test for symmetry where the ends can't be found to flip it for that test?
Agreed.
We have no testable premises to make one view more better than annuder.
The analogy is to emphasize that even when entropy decreases (in one spot) the overall entropy for the Universe increases. Stars are losing their available energy every second, thus entropy is increasing.
The lowest state of entropy was during the beginning. Hydrogen gives us the best known energy production so its creation required the lowest entropy state, thus at the beginning. Fusion ever since has increased entropy.
Entropy is defined as heat flow along an isotherm, so yes, it is a difference in two states. Some just use the "negative entropy" as a way to state a direction a process is going between two states.