The letter was addressed to Jew and Gentile, agree.
Though Paul is explaining why the Jews were severed from Christ, from the tree of life.
Paul also is directly addressing the Jews as the quote below shows.
Romans 2:24
For “the name of God is blasphemed among the Gentiles because of you,” just as it is written.
We can clearly see that Paul is slowly explaining why Israel failed.
Context, context.
The Jews were foreknown by God, fact.
You said, "Romans 11:1-2 is speaking of those among the nation of Israel who were foreknown by God unto salvation and called the remnant and not every person with an Israeli passport!"
That's your interpretation, just read the text itself.
That has nothing to do with the usage of 'foreknew or foreknown' in the text.
'Foreknown' strictly applies to Israel in Romans 11:2. The Gentiles were not the subject of
Romans 11:2, Israel was!
Romans 11:2
God has not rejected His people (Israel) whom He foreknew.
Reading in the context of Romans 2 to Romans 11, we now know how to read Romans 8.
Romans 8:29
For whom He foreknew (Israel), He also predestined to be conformed to the image of His Son,
that He might be the firstborn among many brethren.
Do you understand what reading in the given context means?
That is why it is not wise for a Calvinist to use quotations from Romans 2 to Romans 11.
God indeed has not rejected His people from the Old Covenant and has chosen a very small remnant from among them just as He has also done among the Gentiles whom He foreknew.
Rom 11:4 But what does the divine response say to him? "I HAVE RESERVED FOR MYSELF SEVEN THOUSAND MEN WHO HAVE NOT BOWED THE KNEE TO BAAL."
Rom 11:5 Even so then, at this present time there is a
remnant according to the election of grace.
These are those to whom the promise was given to Abraham.
Gal 3:7 Therefore know that
only those who are of faith are sons of Abraham.
Gal 3:8 And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel to Abraham beforehand, saying, "
In you all the nations shall be blessed."
Gal 3:16 Now to Abraham and his Seed were the promises made. He does not say, "And to seeds," as of many, but as of one, "AND TO YOUR SEED," who is Christ.
Gal 3:28 There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus.
Gal 3:29 And if you are Christ's, then you are Abraham's seed, and heirs according to the promise.
Gal 4:9 But now after you have known God,
or rather are known by God, how is it that you turn again to the weak and beggarly elements, to which you desire again to be in bondage?