Lot's of rum
Some interesting stuff to plunder (be it ships, coastal settings, underwater locations ). Make it exotic, more seafood attacking !
Have the players be aware of this being a very social AP and prepare their characters accordingly.
Keep a bunch of interesting social NPCs (pirates, governors, traders, chieftains ) at hand for the players to interact with or play off-on.
Reduce the "duengeoncrafting" in Parts IV-VI. Reduce some deadliness in AP-I
Keep the BBEG more present and a hassle to the players
So a number of you GM's have run at least part of the AP so far.
What are the major pointers that need to be kept in mind?
What would you change if you ran it again?
What worked to keep players in the action without railroading?
To be honest, and this might sound simplistic, but we've found that one way to keep things on track is to agree on a general idea, a rough overall goal ahead of time in line with that presented in the AP. No spoilers really, but if its agreed ahead of time that the players are going into this AP with the intentions of making themselves notorious pirates, of climbing the ranks of the pirate hiearchy and carving out a slice of legend for themselves, well... let's just say that it goes a long way towards keeping things on track. Characters made with some other long-term goal in mind might find themselves caught between what they want to do and what the AP wants them to do which won't be good for anyone.