Tell me how you can understand history without understanding physics, how you can understand ecology without understanding chemistry, how you can understand poetry without understanding psychology. The world itself is interdisciplinary. Relational thinking is easy to define - it is thinking without boundaries - nothing is off topic.
You yourself showed how analogies are empirically real. Therefore I do not understand why you think it is at odds with empiricism.
Please elaborate on exactly why you think event horizons constitute a total lack of connection between one thing and another thing. My understanding of event horizons is that A) they are not as cut and dry as you describe, eg Hawking radiation, and B), it makes no difference since event horizons arise within time and space, and therefore there is a chronological connection even if there is not a connection in the present moment. Suppose for example that before the big bang there was a larger universe which spawned 100 "big bangs" - their own separate universes that cease to have contact with any other thereafter. The conditions in the original universe that gave rise to each still shape each, and each continues to be connected on that basis, on the basis of the broad Universe that contains all of these.
The word universe can be complicated for this reason, because in astrophysics it means the observable universe, but in metaphysics it means the sum of reality, which does not necessarily cohere exactly with the observable universe, though it certainly would contain it.
The other objection I have is one you yourself raised already - even if you theoretically have two entities in one universe, A and B, that are totally "unconnected" from each other in that they do not influence each other, assuming that each obeys a universal law (i.e. they are themselves both contained in a larger universe), they are connected on that basis, that is, their parentage is the same, and the behavior of each is predicted on a common basis, one of connection.
If you can show me something that exists outside the universe, I welcome the attempt.