What is your point in bringing up Luke 13:33? You already acknowledged that John 19:20 and Hebrews 13:12 place the crucifixion outside of the city gate, so Luke 13:33 doesn't change that. So, what are you trying to say by bringing up Luke 13:33? When Jesus referred to Jerusalem in Luke 13:33-34 was He talking about the physical city or the people? It should be obvious because it was the people who had Him killed, and obviously not the physical city of Jerusalem itself.
The context of that is that He would be sentenced to death in Jerusalem, not actually crucified there. Revelation 11:8 talks about the place where He was crucified, not the place where He was sentenced to death..
It contradicts the idea that He was crucified within the city of Jerusalem. He was not.
It rules out the possibility that Jesus was crucified in the city of Jerusalem. No, John 19:20 and Hebrews 13:12 explicitly state otherwise.
Do you just assume that Babylon refers to a literal, earthly city just because it's called a city? It's a symbolic entity, not a literal, earthly one. It's also called a woman/harlot, but obviously isn't a literal woman/harlot. I believe it represents the spiritual opposite of the New Jerusalem, of which all believers are part (Galatians 4:26, Hebrews 12:22).