This is my plan starting in phase 4. What I will be doing launch day will be whatever things on this list I don't get done during phase 4 and early access.
1) Chocobo from Grodania to check ferry price.
1a) if the ferry is cheap: take ferry to Limsa and unlock Arcanist.
2) Sort inventory. This step will take most of a day. /cry
3) get to the point in the story that unlocks airship. Will use ACN for this if I unlocked it. If not I will use PGL or GLA so exp won't be wasted.
3a) Unlock ACN if I haven't already.
4) Level BTN to 20 if still in phase 4. 23 if after.
5) Get to the point of the story where I rejoin my GC while leveling ACN. I'll probably use CNJ in the dungeons and party instance because so many people will be wanting to use ACN.