[Dutchboy88]

"But as you just said, he’d never been in Rome. So how did he notice that the church in Rome was having these problems?"

He had been advised from folks who lived there. Quite possibly by Aquila & Priscilla, Jewish believers run out of Rome in circa 49AD, whom he had met in Corinth. Acts 18:1ff. This meeting was some 5 - 7 years before the letter to Rome was written. Once A & P were back in Rome, they probably wrote him about the problem. Notice Rom. 16:3

But, clearly Paul had never been to Rome until his capture later. Rom. 1:13ff.

[BenKenobi]

“He had been advised from folks who lived there.”

That would imply organization, would it not, such that Paul would be informed of goings on in distant cities. See, you can’t square the circle. The communities were in communication with each other and they had an established heirarchy in the Apostles, who were their caretakers.