I'll try to answer in as few words as I can.
I'll preface by saying that the path to salvation has always been open to all people thru out all time, from the time God created Adam.
Yes, the NT is written to all, with no respecter of persons.
Some may argue, it's ok, I believe that the Apostles are part of the "Church". I could easily be wrong, but I believe that the "Church age" started with Pentecost, when the Holy Spirit, (for the first time,) came into and stayed within believers on a 24/7/365 basis.
And I do believe that the Apostles, and all the believers of both Jew and Gentile, whether having died or are living at the time of the Rapture will be "Taken away/snatched away/raptured", "The dead in Christ shall rise first, then we who are alive will be caught-up together with them in the clouds to meet the Lord in the air".
You asked me about programs for Jew/non-Jew in regards to "end times".
How do we define "end times", 2,000 years ago the Thessalonians thought they were in "end times".
The modern thought is that "end times" started in 1948 with the re-birth of the nation of Israel.
My personal view is that the "real end times", (so to speak,) started when there were no prophecies left that "had" be fulfilled before a rapture could take place, I believe the Rapture could happen any day.
Jesus told the disciples a list of things that would happen before He returned, (Jesus was talking about when He would physically return to earth, not a "rapture").
When the disciples were asking Jesus all this stuff the cross event had not yet taken place, Jesus had not risen, and the Holy Spirit had not yet descended, and the disciples were still "under the law".
Even though Jesus had talked to them about the "Kingdom of Heaven" they still were looking for Him to be their King on an earthly kingdom.
They were shocked when He told them He must die/rise/go back to heaven.
So, they were asking him what the signs of would be his coming back to earth, and He answered them.
Jesus was not teaching "Rapture Theology" to the disciples, He was simply telling them things that would take place, and when they saw the "beginning" of those things to "Look-Up" that their redemption was near.
Different programs?
Yes, during the 7 years of Tribulation, (some say 3-1/2 years of Tribulation plus 3-1/2 years of Great Tribulation,) that's ok, there are different programs.
That's easy to see, suffice to say that the "man of sin" does not declare himself god in China, and the Armageddon battle doesn't take place on the plains of Kansas.
Both Jew and Gentile, if they die having rejected Christ both go to destruction.
Sin had enveloped the world, so God re-started with Noah and then chose Abraham to father a people that would (hopefully,) show the world that salvation from sin would come from God giving grace to those who would follow Him.
In effect, the Jewish people were supposed to do two things; 1, Be the caretakers of Gods Land, (Israel). 2, Be the "missionaries" of the world , (so to speak),
Well, for 2,000 years that didn't work out so well, so God sent Jesus, and the Jews rejected Him.
What could God do? From the snake in the Garden to Noah was roughly 2,000 years of rejection, then came rejection of the Messiah after roughly 2,000 years since Abraham, so then God gave the Gentiles about 2,000 years to accept Him as Lord and Savior over all.
Well, we've seen how the roughly three periods of about 2,000 years have worked out, right?
I'm not saying this lightly by any means, but God has been an "equal opportunity employer" in trying to get mans attention for the last ~6,000 years, and man has had his "3 strikes and you're out".
1, Adam to Noah, sin take over, God is rejected, that's strike 1.
2, Abram/Jews, reject the messiah, that's strike 2.
3, "The time of the Gentiles", further rejection of God, that's strike 3.
Man is OUT, and God comes to bat.
When the Tribulation starts God is going to be at home-plate, and He's going to be swinging a big bat, and the world is going to learn how hard He hits the ball.