What books are in your OT? How do you know they are the right ones? People who walked with Jesus=Founders of the early Church at Pentecost so that encapsulates your last two points. How do you differentiate the People who walked with Jesus as guided from the Holy Spirit from the Church? Using the texts you have available in 33 AD?
Christ cited the Law and the Prophets and specifically referenced Jeremiah, Isaiah, Jonah and some others I can't recall at the moment. He also quoted David, who isn't traditionally thought of as a prophet. So I am comfortable using these, as well as other scriptures specifically referred to by NT authors.
I see no need to differentiate them from the early church. But I'm going off what they wrote. Not what someone else wrote about what they wrote.