This is Michael Bird’s list:
Why Did Saul of Tarsus Persecute the Church?
The Origin of Paul’s Gospel?
Paul and the Beginnings of the Gentile Mission
Paul and the Antioch Episode
Paul’s Problem with the Law
Paul and His Opponents
The Pauline Hermeneutic: Paul and Israel’s Sacred Traditions
The Purpose of Romans
Paul and the Parting of the Ways
The Quest for the Centrum Paulinium
Here’s my own list, like Michael’s rated in no particular order.
Paul’s Reasons for Persecuting the Church
Paul’s View of the Resurrection
The Origins of the Gentile Mission
The Antioch Incident
Paul’s Relationship to Jerusalem
Paul’s Relationship to the Synagogue
Paul’s Critique of the Law
Paul’s Meaning of “Righteousness” (and how central was the idea)
Paul’s View of Salvation History (or lack thereof)
Paul’s Inconsistencies and/or Evolution of Thought (reasons for)