I said the 12 + James, and I gave you Acts 8:1.
If you want to believe otherwise, I am fine.
Sure Acts 8:1 shows their love for and focus on Jerusalem.
Generally speaking they saw that as their general focus - while the 'new' apostle Paul had the amazing ministry to the Gentiles.
But it was not as segregated as you claimed
when you said:
"The 12 + James never left Jerusalem in their lifetime, because the nation of Israel never accepted Christ as their Messiah. Cornelius was a one off incident and he was saved under the same program that Israel had."
Cornelius WAS saved by the gospel - read the chapter! And the whole point of it was that he was not a Jew, but a Gentile - so this business of being "saved under the same program that Israel had" is not true. Peter's talk might have had some rhetorical flourish in the way he said "as you already know" or it might have actually been the case. But whatever the matter before Peter's arrival, by the end of the chapter Cornelius is a gospel believing spirit filled Gentile. And it took Peter and John - 2 of the 12, to actually leave Jerusalem.
Oh - then you want us to forget that Peter goes to Lydda, then Joppa, then in 10:23 Caesarea / Cornelius.
Acts 9:32–43
And as I said, other senior church leaders from Jerusalem were also sent out. I grant Philip the evangelist is not one of the 12, but a senior leader. It shows while they where primarily caught up in the ministry in Jerusalem, there was some overlap with Gentile ministry in other cities as well.
(
Acts 8:5 Samaria, 8:40 then Caesarea.)