Then of what relevance is it that none of the other apostles wrote to the Gentile churches presenting the regulations Paul presented to them?
All teaching of Christ's apostles, including Paul, is apostolic teaching.
For the people he was writing to, maybe; not for us.
Some of Paul's churches were writing to him with specific questions, or there were things going on in that church that Paul needed to address.
It is not Apostolic teaching, for example, that women shouldn't wear gold. And it's certainly not upheld today - or women wouldn't have gold wedding rings in church. It is not Apostolic teaching that women cannot braid their hair, or have to cover their heads.
Then of what relevance is it that none of the other apostles wrote to the Gentile churches presenting the regulations Paul presented to them?
So the apostles James', John's or Peter's letters to the churches are supposed to be identical to the apostle Paul's letters to the churches?
Did I say that?
Of course they're not. But if there were a specific doctrine, especially one of importance, you'd expect all the Apostles to teach it to all their churches. And not just have it "taught" by one person in a personal letter - which was one of the last that he ever wrote.
Paul's apostolic teaching is either the word of God authoritative to the whole church, or it is not.
Teaching, yes.
Personal greetings, advice or answering specific problems in certain churches, no.
For example, one of the verses you quoted appears to suggest that Paul had a problem with women speaking in church.
If by that he meant that women should learn in silence and not interrupt, fair enough; that goes for men too.
If you interpret that to mean that no woman should speak in a service - as some do - then you have to explain why Paul taught that women may pray and prophesy. Or why Paul had several, valued female co-workers. Or why he trusted Phoebe to take, and read, his letter to the church at Rome. Or why he called Junias "outstanding among the apostles." If women can't teach, why did Paul not say that the gifts of the Spirit, which include Pastors and teachers, should only be men?
Either it was "Apostolic teaching" that women can't speak/teach in church, or it is Apostolic teaching that the gifts of the Spirit - teaching, evangelism, prophecy are available to all and that God can raise up whoever he wants to serve him in whatever way he chooses - just as he raised Deborah up to be judge over all Israel.
Yeah. . .isn't there something about a council meeting where they were all caught up to the third heaven and heard things they were not allowed to repeat?
No, Paul says "a man", 2 Corinthians 12:2-4 - largely thought to be referring to himself.
Wasn't that the same Council/meeting where they decided to place Paul's letters on the same level of authority as the God-breathed writings of the OT (2 Pe 3:16)?
It wasn't a council meeting, but a personal experience.
All letters written to the churches by the apostles of Jesus Christ (e.g., Peter, John, Paul) are by definition Apostolic teaching.
I'm sure that when Paul wrote to people to say they should treat their slaves well, those words were sincere; even inspired by God.
We don't have slaves today - and I think the church played a part in getting slavery abolished. So how do we apply that "apostolic teaching", not to mention all the other examples I have given, today?
And are you really saying that if there was a young widow who had lost her husband in war and who came to your church for help, you would all turn her away because Paul says that widows under 60 deserve no help and are gossiping busybodies?