Do you think that the teachings of St. Paul were NOT God-breathed when he preached them, but WERE God-breathed when he wrote them?
“Do you think that the teachings of St. Paul were NOT God-breathed when he preached them”
Correct. He taught with authority. His teachings were not equivalent to Scripture in the way you are asking.
” but WERE God-breathed when he wrote them?”
He did not simply “write them.”
He was moved by the Holy Spirit and the Scriptures were “God-breathed” as detailed in Scripture.