I don't know, I believe that Israel is a real people, not something inside individuals, just as the land Abrham was told to 'walk' was not some spiritual land, it is real and cannot be spiritualized away.
The Jews have much prophecy to fulfill, see Jer. 32:32 onward, moreover, we read that 'all Israel shall be saved'.
Yes, the goy were graphed in, and this is important. Note that it was not some unusual thing Paul was explaining to them, for in their times it was common to take an olive tree that was not bearing fruit, and graphed in a wild olive branch, and this for the purpose of coaxing the true tree to bear it's fruit. So this would have been well understood and a perfect example, which is why the Holy Spirit inspired Paul to write about it in that way. The goy were graphed in, but not so they would bear any fruit of their own, but so that Israel would be made jealous and bear the fruit of repentance. REmember the instructions from the beginning of the Lord's ministry, was to repent and turn, that is to say, re turn to that which they had turned away from. It is the instruction to he Jews from Peter thoroughly in the beginning chapters of Acts he is driving the point forward and home. At tjat time, the goy had no hope of their own, was without God in the world :
AV Eph 2:12 That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:
But they did not repent. And it was not until the end of Acts that the salvation of God is sent to the nations. Not until the revelation of the mystery as given to Paul the prisoner do gentiles as such, have a message of their own, a hope of their own, a blessing apart from Israel. So I agree with you, the goy had no knowledge, they were without God in the world, having no hope apart from Israel's preeminent position. Heck, they worshipped every god, a whole pantheon of gods, one for every day, and it wouldn't have matter much if the next god to come along was real or not, they would have worshiped the next one as well, heck, they even had a sign, 'to the unknown god' - lest they leave any gods out.
But Paul strives to reveal to us all that while Israel is not now being used as a blessing, gentiles are blessed anyway. And they are blessed, not in faithful Abraham, but even better, they are blessed in Christ in the heavenly places. Paul says it like this:
AV Eph 1:3 . Blessed [be] the God and Father of our Lord Jesus Christ, who hath blessed us with all spiritual blessings in heavenly [places] in Christ:
& AV Eph 3:1 . For this cause I Paul, the prisoner of Jesus Christ for you Gentiles,
(IN Acts 28 he was a prisoner in bonds/chains for the hope of Israel - this is different)
AV Eph 3:2 If ye have heard of the dispensation of the grace of God which is given me to you-ward:
AV Eph 3:3 How that by revelation he made known unto me the mystery; (as I wrote afore in few words,
AV Eph 3:5 Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit;
he then elaborates elsewhere:
AV Phl 3:5 Circumcised the eighth day, of the stock of Israel, [of] the tribe of Benjamin, an Hebrew of the Hebrews; as touching the law, a Pharisee;
AV Phl 3:6 Concerning zeal, persecuting the church; touching the righteousness which is in the law, blameless.
AV Phl 3:7 But what things were gain to me, those I counted loss for Christ.
AV Phl 3:8 Yea doubtless, and I count all things [but] loss for the excellency of the knowledge of Christ Jesus my Lord: for whom I have suffered the loss of all things, and do count them [but] dung, that I may win Christ,
Phl 3:9 . And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:
AV Phl 3:10 That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death;
AV Phl 3:11 If by any means I might attain unto the resurrection of the dead.
Now this is not an ordinary resurrection, it is the out resurrection out from among the dead ones. Paul counts now, after Acts, and after he revelation of the mystery, he counts as dung those things which just before he had counted for gain. Namely, his heritage, being a Hebrew and so forth, but for this high calling, not the kingdom coming tothe earth, but this super heavenly calling he is revealing revealing revealing, Paul says he puts those things behind him and reaches forth to those things ahead of him, which is this new creation he is revealing as the mystery body:
AV Phl 3:13 Brethren, I count not myself to have apprehended: but [this] one thing [I do], forgetting those things which are behind, and reaching forth unto those things which are before,
AV Phl 3:14 I press toward the mark for the prize of the high calling of God in Christ Jesus.
AV Phl 3:15 . Let us therefore, as many as be perfect, be thus minded: and if in any thing ye be otherwise minded, God shall reveal even this unto you.
So what is Paul talking about? It is none other than that mystery which God had hid in Himself from ages of time and from generations of men, but now is being made known to all nations.
Eph - the fulness
Col is the sister letter - the oneness
Philps - the emptying
2 Tim - further instruction and practical outworking