No problem, Rufus, I very much respect your point of view very much, so I definitely accept that you could be correct. Given as I tend to be a lazy cuss and generally a simple minded who doesn't like to think much, I'll try to provide a quick answer right now, and if you don't feel that sufficient, I'll try to address your post tomorrow (or so), in greater detail regarding the points you raise above.
First and foremost is your point of "children of promise" "according to election". If I've understood you correctly, it seems to me that both parts cannot equally be true at the same time, that is, logically, one must take full precedence and eliminate the possibility of the other: either someone is chosen solely and exclusively because they had been elected (in which case, being a Jew is irrelevant), or they had been elected because they're Jews (in which case being elect is irrelevant) - at least according to my understanding of election. However, if you're making the case that both can be true, then that would imply that God must have TWO salvation plans, not one: one with Christ solely as the Savior, having exclusively chosen who would become saved through His prerogative, with no other factors permitted; the other, that human linage has played a part in it, which in itself, would override the Christ's choice. I guess you might say that Christ's choice factored into it that they would become Jews and chose them on that basis, (but in that case, wouldn't it eliminate non-Jews?). However, for that option to be logically consistent, it would seem to have to hold true across all Jews not just some - that all must become saved, if its basis were they are Jews.
The second reason is the following verses, which, I believe, reveals to us who the "His people" now are: the true spiritual Israel and true spiritual Jews. It seems to me that by the verses, that God has pretty much wiped the slate clean regarding His relationship to the earthly nation of Israel and to its Jews, which He warned that He would do should they violate the stipulations of His covenant with them, which they nevertheless did repeatedly.
Hope this makes sense; writing isn't my strong suit.
[Gal 6:15-16 KJV]
15 For in Christ Jesus neither circumcision availeth any thing, nor uncircumcision, but a new creature.
16 And as many as walk according to this rule, peace [be] on them, and mercy, and upon the Israel of God.
[1Pe 2:9-10 KJV]
9 But ye [are] a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light:
10 Which in time past [were] not a people, but [are] now the people of God: which had not obtained mercy, but now have obtained mercy.
To set the stage, God told us this:
[Hos 1:9-11 KJV]
9 Then said [God], Call his name Loammi: for ye [are] not my people, and I will not be your [God].
10 Yet the number of the children of Israel shall be as the sand of the sea, which cannot be measured nor numbered; and it shall come to pass, [that] in the place where it was said unto them, Ye [are] not my people, [there] it shall be said unto them, [Ye are] the sons of the living God.
11 Then shall the children of Judah and the children of Israel be gathered together, and appoint themselves one head, and they shall come up out of the land: for great [shall be] the day of Jezreel.
[Rom 9:30-33 KJV]
30 What shall we say then? That the Gentiles, which followed not after righteousness, have attained to righteousness, even the righteousness which is of faith.
31 But Israel, which followed after the law of righteousness, hath not attained to the law of righteousness.
32 Wherefore? Because [they sought it] not by faith, but as it were by the works of the law. For they stumbled at that stumblingstone; 33 As it is written, Behold, I lay in Sion a stumblingstone and rock of offence: and whosoever believeth on him shall not be ashamed.