To the Jews he would say he was for the law, but would stress the prophecies of Christ and His gentle commandments - I do not think he taught them to keep all the old traditions, rituals and practices. He was trying to teach them the true spiritual law I think, but they would think "rituals" when the word "law" was used.
To the Gentiles he would preach against "the law" meaning the rituals and feast keeping and the other rote practices of Judaism, and would stress that Christ fulfilled the law, and that they did not have to follow those rote legal traditions but were "freed" from the "law."
So he was preaching to their thought processes to try to help them understand.
This is why I think he is confusing. Because among other things he uses the word "law" differently in different contexts. Somewhat similarly with "faith" and "salvation." I believe there are modern Christian sects which take passages from his epistles all too literally, and in an interpretation which conflicts with the very words of Christ.
I don't find Paul to be rogue, but just interpreted too literally or legalistically at times.