Steve,
I appreciate the time you've taken to dissect my argument. I disagree with the conlusion of your syllogism, which I will get to momentarily.
The fact that the Gentiles are not specifically mentioned in the earliest verses of chapter nine, where Paul is ramping up his argument by making his first point, does not justify our ignoring the corresponding part of his argument in the remainder of the discussion.
Taken alone, I see Israel and Gentiles as distinct ethnic entities throughout Romans 9-11. IMO, to argue that the church is Israel one would need to point to other texts outside of these chapters (even these are suspect, IMO). When Gentile inclusion is first mentioned in Romans 9:24 (
even us whom He called, not of the Jews only, but also of the Gentiles?), it merely says that in addition to the Jews the Gentiles have also been called. God had
"prepared beforehand for glory" both Jew Gentile. After all, that is why Abram's name was later changed to Abraham, signifying that he would be a father of many nations (not the Jews alone). Paul could tell the Thessalonian church with confidence:
But we are bound to give thanks to God always for you, brethren beloved by the Lord, because God from the beginning chose you for salvation through sanctification by the Spirit and belief in the truth, 14 to which He called you by our gospel, for the obtaining of the glory of our Lord Jesus Christ.
I see nothing here indicating that Israel should be considered the entire body of Christ. Israel is made up of believers and unbelievers. Those believers are part of the church, but the enitity "Israel" does not make up the entire church. In the first century, Israel (at large) stumbled over that stumbling stone. Paul could say in chapter 11
"God has given them a spirit of stupor, Eyes that they should not see And ears that they should not hear, To this very day." In the same chapter, Paul also quoted David who said
"that their eyes were darkened so that they could not see." Israel had not obtained what it sought, as verse 7 spells out. This assessement of Israel's condition follows
after Paul made the assertion that "
at this present time there is a remnant according to the election of grace."
If this remnant was all that the prophets foretold, why all the discouragement from Paul? Why all the negativity? Why isn't Paul rejoicing over the remnant of Israel being saved during his lifetime? Because there's more to it, IMO. Paul continues:
"I say then, have they stumbled that they should fall? Certainly not! But through their fall, to provoke them to jealousy, salvation has come to the Gentiles. 12 Now if their fall is riches for the world, and their failure riches for the Gentiles, how much more their fullness! ... 15 For if their being cast away is the reconciling of the world, what will their acceptance be but life from the dead? This is very strong language that there is much more to the spiritual condition of Israel (perhaps in the future?

than what Paul experienced first hand and what they would continue to experience during their
"partial blindness."
We've discussed the following verses already, but I think they are still germane to the discussion:
25 For I do not desire, brethren, that you should be ignorant of this mystery, lest you should be wise in your own opinion, that blindness in part has happened to Israel until the fullness of the Gentiles has come in. 26 And so all Israel will be saved, as it is written: "The Deliverer will come out of Zion, And He will turn away ungodliness from Jacob; 27 For this is My covenant with them, When I take away their sins." 28 Concerning the gospel they are enemies for your sake, but concerning the election they are beloved for the sake of the fathers.
As I said previously, I believe that "Israel" of verse 26 is also ethnic Israel in verse 25. (Since Jew and Gentile have been ethnically distinct throughout Romans 9-11, I see no warrant to refer to "Israel" of verse 26 as the body of Christ.) IMO, this passage is saying that many Jews will be saved at the coming of Christ. And notice Paul's continuation here: concerning the gospel they (the Jews) are enemies (true), but concerning the election they (the Jews) are beloved for the sake of the fathers. Paul is still drawing an ethnic distinction between Jew and Gentile.
I disagree with the conclusion of your syllogism which states that "Paul identifies the Body of Christ, or the Church with Israel." The olive tree indeed represents Israel, and the Gentile believers, acccording to Paul are now
"partakers of the root and fatness of the olive tree". Elsewhere Paul states that Gentiles were
"strangers from the covenants of promise" and through the blood of Christ were "brought near" to Israel, that is, they are now the benefactors of all the promises given to the patriarchs (
they partake in the root and fatness of the olive tree). We (Gentile believers) have been grafted in to share in all the blessings that were promised to Israel through the patriarchs, but we do not become Israel (see comments above)
Let me know if I've met your expectations.
Brian