I've read it a ton.
You mention the beginning of Romans. Great. Lets look at it.
Now why did you go and skip the opening which shows who the Romans were, that they had "a faith (not a mutual faith of Paul and them) and their need to be established by Paul's gospel (the gospel of Christ)? What an odd thing to do for someone who wants it to appear as though they want us all to "look at it".
Romans 1:1 Paul, a servant of Jesus Christ, called to be an apostle, separated unto the gospel of God,
Romans 1:2 (Which he had promised afore by his prophets in the holy scriptures,)
Romans 1:3 Concerning his Son Jesus Christ our Lord, which was made of the seed of David according to the flesh;
Romans 1:4 And declared to be the Son of God with power, according to the spirit of holiness, by the resurrection from the dead:
Romans 1:5 By whom we have received grace and apostleship, for obedience to the faith among all nations, for his name:
Romans 1:6 Among whom are ye also the called of Jesus Christ:
Romans 1:7
To all that be in Rome, beloved of God, called to be saints: Grace to you and peace from God our Father, and the Lord Jesus Christ.
Romans 1:8 First, I thank my God through Jesus Christ for you all, that
your faith is spoken of throughout the whole world.
Romans 1:9 For God is my witness, whom I serve with my spirit in the gospel of his Son, that without ceasing
I make mention of you always in my prayers;
Romans 1:10
Making request, if by any means now at length I might have a prosperous journey by the will of God to come unto you.
Romans 1:11 For
I long to see you, that I may impart unto you some spiritual gift, to the end ye may be established;
Romans 1:12
That is, that I may be comforted together with you by the mutual faith both of you and me.
Romans 1:13 Now I would not have you ignorant, brethren, that oftentimes I purposed to come unto you, (but was let hitherto,)
that I might have some fruit among you also, even as among other Gentiles.
Romans 1:14 I am debtor both to the Greeks, and to the Barbarians; both to the wise, and to the unwise.
Romans 1:15
So, as much as in me is, I am ready to preach the gospel to you that are at Rome also.
Romans 1:16
For I am not ashamed of the gospel of Christ: for it is the power of God unto salvation to every one that believeth; to the Jew first, and also to the Greek.
Romans 1:17
For therein is the righteousness of God revealed from faith to faith: as it is written, The just shall live by faith.
They weren't saved at the writing of the Roman letter. That is why Paul wrote to them to establish them with the gospel of Christ! There's no need to do that if they are already saved. It shoots your whole grafting in to the ground as Paul is telling them of the position they held BEFORE THEY WERE SAVED ("wert graffed in"). It also explain s how it is that they were in jeopardy of being cut off (which is impossible for members of the BoC).