I have actually been part of this discussion from the earliest part.
Actually, I correctly identified Babylon the Great as Rome very early in the thread, before you elaborated on extraneous church traditions (some of which necessarily sought to make the identity more consistent for later contemporary Christianity), which were of some historical interest but tend to muddy the waters about the original actual meaning.
Babylon the Great was Rome—a city on seven hills, and a city with a kingdom over other kings (basileus, βασιλεύς, Strong’s G935), the specific term used when referring to kings of Rome’s clients kingdoms (e.g, Herod at Matthew 2:3 and Mark 6:14). Jerusalem held no such position, and other proposed identities just get more and more fanciful.