I don't quite understand the modern movement to denigrate the Apostle Peter as if by any means it must twist the Scripture. I see flaws in your contentions and there is so little time so I'll only address a side issue for now specifically. Every Apostle presented the Gospel to the Jew first, as they should for it is written: 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.
Galatians 2:7 But on the contrary, seeing that I had been entrusted with the gospel to the uncircumcised, just as Peter had been to the circumcised
The verse you quote from Romans confirms Galatians 2:7.
Part of the issue with Peter is the RCC's attempts to elevate Peter into something not intended by the Bible.
There has been no attempt to denigrate Peter. Only to look at Peter in the proper Biblical context.