Paul's Missionary Journeys?

In NT studies it is common to refer to Paul's three "missionary journeys", but I think this privileges the information we have in Acts and somewhat neglects the evidence of Paul's letters. I think it better to think in terms of:

1. Paul's Arabian mission centred around Damascus and Arabia.
2. Paul's Syrian mission located in Antioch.
3. Paul's Cypriot/Asian Mission.
4. Paul's Aegean Mission.
5. Paul's Journey to Rome.

Paul: Conversion, Commission, and Chronology

When did Paul get his "commission" to go to the Gentiles? Was it on the Damascus Road (e.g. Gal. 1.13-14; Acts 26:14-15) or a subsequent relevation, or then again was it something that only became clearer to him later on in his ministry (Acts 22.17-18)? If this call only came into perspective later on, did Paul consider his period of time in Arabia as part of his call to go to the Gentiles (Gal. 1.17). One of our HTC students, David Kirk, has a good run down on this.