Brother, I appreciate the time you put into this. Let me just address the central point, because everything else in your post depends on it.
You’re assuming that the word apostle is used only for men holding a fixed, numbered office. But Scripture itself uses ἀπόστολος in more than one way. Barnabas is explicitly called an apostle in Acts 14:14, and nothing in the text ties that usage to the foundational office Christ gave the Twelve.
I do not think I am assuming anything. I am reading the word apostle from the scriptures. It is used in a certain context in the scriptures. Certain powers and spiritual gifts are associated with this office that are not associated with other believers. They are kingdom signs because apostle is in the context of God's rule over the earth. The very power of Christ was delegated to them, including power to raise the dead. They were for the purpose of confirming the gospel of Christ. Words and context are important in the scriptures.
Consider what Paul said when his apostleship was challenged by the apostates in Corinth.
1 Cor 12:11 I am become a fool in glorying; ye have compelled me: for I ought to have been commended of you: for in nothing am I behind the very chiefest apostles, though I be nothing.
12 Truly the signs of an apostle were wrought among you in all patience, in signs, and wonders, and mighty deeds.
13 For what is it wherein ye were inferior to other churches, except it be that I myself was not burdensome to you? forgive me this wrong.
So you see an apostle is invested with gifts from the LORD that distinguishes their office from all others
The same is true of Andronicus and Junia (Romans 16:7), and of Silas and Timothy in 1 Thessalonians 2:6. These men were not part of the Twelve, nor part of any numbered group. They were “sent ones,” raised up by the Spirit and sent out by the churches.
That broader usage is simply there in the text. Luke uses the word that way. Paul uses the word that way. It isn’t a theory, it’s the vocabulary of Scripture.
I see your point but I disagree with your premise that these two men are being singled out as apostles in any particular way. Paul said this about Rufus in verse 13 just a couple verses later;
"Salute Rufus chosen in the Lord, and his mother and mine."
This obviously is conversational language and not an attempt to suggest he and Rufus are in the same family tree. Paul is not suggesting that Andronicus and Junia, Jews, are apostles in any way but they had ministered faithfully with the apostles at some point in their lives. Remember that Romans was penned in AD 58 when the church was already 28 years old.
In Acts 14 Luke used matter of fact language when referring to Barnabas as an apostle. The reaction of both Paul and Barnabas to those in Lystra was in the context of what the use of the sign gifts of the apostles had caused as a response of those who witnessed the miracle. Barnabas was associated with Paul in his office as apostle and that is what the text tells us. Luke could have used the word "servants" to describe this event if indeed it was what he meant. I have complete confidence in the accuracy of the words in my Bible. Servanthood and apostleship are separated in the scriptures. All apostles are servants but not all servants are apostles. I will demonstrate this.
Romans 1:1 Paul, a servant of Jesus Christ, called to be an apostle, separated unto the gospel of God,
Titus 1:1 Paul, a servant of God, and an apostle of Jesus Christ, according to the faith of God s elect, and the acknowledging of the truth which is after godliness;
2 Peter 1:1 Simon Peter, a servant and an apostle of Jesus Christ, to them that have obtained like precious faith with us through the righteousness of God and our Saviour Jesus Christ:
Only a limited number of Christians can claim to be both and they will be a servant first.
Concerning Silas, he is referred to in his kingdom office as a "prophet" This is a distinct office of the kingdom and is foundational to the church of Jesus Christ. We are told this by Luke.
Ac 15:32 And Judas and Silas, being prophets also themselves, exhorted the brethren with many words, and confirmed them.
We know from our reading how the word of God was confirmed in the apostolic era of the Christian church. It was by miracles and sign gifts the apostles and prophets had been given in Matthew 10 and Luke 10 respectively for that purpose.
He 2:3 How shall we escape, if we neglect so great salvation; which at the first began to be spoken by the Lord, and was confirmed unto us by them that heard him;
4 God also bearing them witness, both with signs and wonders, and with divers miracles, and gifts of the Holy Ghost, according to his own will?
1Co 1:22 For the Jews require a sign, and the Greeks seek after wisdom:
The Twelve, on the other hand, held a unique, foundational office tied to their eyewitness role and their direct commission from Christ. Matthias was added to that number, and Luke records it without any correction or reservation. When Luke later says “the eleven,” he is using the same shorthand he used in his Gospel, a narrative label, not a doctrinal headcount. Paul does the same thing when he refers to “the twelve” in 1 Corinthians 15:5, even though Judas was already gone. These are narrative designations, not theological limits.
There are limits in these offices relative to the eternal order and the names of these men who hold these offices are revealed through the words of scripture. However, the answers to our questions requires study. There are names of the apostles on the foundations of New Jerusalem and there are only 12.
Eph 2:
19 Now therefore ye are no more strangers and foreigners, but fellowcitizens with the saints, and of the household of God;
20
And are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner [stone];
21 In whom all the building fitly framed together groweth unto an holy temple in the Lord:
22 In whom ye also are builded together for an habitation of God through the Spirit.
So the distinction is simple:
There is the foundational office held by the Twelve (and Paul), and there is the broader functional use of the word for men sent out by the churches. Scripture uses both. That’s all I’m saying.
I can see your point in possibly one verse, 1 Thess 2:6. The phrase "as apostles" is definitely in the text, but it takes two mentions to build a doctrine.
I appreciate your desire for precision in the words God chose. I share that desire. But the precision has to begin with how Scripture itself uses the vocabulary, not with a fixed number imposed on the text.
Thank you for expressing your belief on the subject. It is obvious we accept the "words" of scripture differently.
Re 21:14 And the wall of the city had twelve foundations, and in them the names of the twelve apostles of the Lamb.
There is another possibility that unfolded in the first 7 chapters of Acts (that is congruous with the hard ground in Mt 13 parable of the Sower) as God called Jerusalem and Judah to repentance, something that was a legitimate call that would have changed history going forward (unless one believes in determinism). Just as Jesus said John the Baptist could be Elijah had Israel received him, I can see that Mathias could have, and probably would have, filled the role of the 12th apostle in that circumstance had Jerusalem repented and believed in Jesus Christ and been baptized in his name. Acts is a history book and God responds to man's obedience to his word. But I may be far off on this.
I respect your opinions and want you to know that because I disagree with you on this subject, I am still your friend.
Compare this prophecy in a parable by Jesus in Luke to these first years in Acts:
Lu 13:5 I tell you, Nay: but, except ye repent, ye shall all likewise perish.
Lu 13:6 He spake also this parable; A certain man had a fig tree planted in his vineyard; and he came and sought fruit thereon, and found none.
7 Then said he unto the dresser of his vineyard, Behold, these three years I come seeking fruit on this fig tree, and find none: cut it down; why cumbereth it the ground?
8 And he answering said unto him, Lord, let it alone this year also, till I shall dig about it, and dung it:
9 And if it bear fruit, well: and if not, then after that thou shalt cut it down.
Who knows if there would have been a Lystra narrative if Israel would have repented?