This was a very interesting adventure to write from a number points, not least of which introducing such high level future enemies in such close quarters to the PCs.
It certainly will be a challenge for some groups to get their heads around this proximity and one thing I've tried to stress is the nature of just how tough the bad guys are on board the vessel. You're the expert at pitching this to your players, what Wormwood does is give you a number of options for you to build upon.
The obvious way here is the NPCs, and there are some immediate potental allies to warn the PCs, but again if this isn't enough you can go with big fights between the tougher NPCs; and wounds that would down the toughest PC in a single go etc.
One thing I was very very mindful of is that the PCs are vulnerable to start with, and the GM needs to play this carefully, their relationship with Plugg is a tricky one - if he hates them it would be easy for him to have them keelhauled, which is why initially he falls into the background as the main villain behind Scourge. The possibilities of bullying the PCs must be carefully avoided too, give them victories along the way
The other issue I thought long about was controlling the PCs action's somehow - it could be too easy for one player to take over a session, which is why I've brought in the actions - to try to make sure that everyone gets a fair crack of the whip (or cat).
Absolutely, the day to day life will work for some, and less so for others, if you like more action pitch in a few more fights or side quests along the way, or skip some of the checks as has already been suggested - the important thing is for the PCs to realise what being a pirate is like for their future careers and most important have fun.
I'm really looking forward also to how GMs will approach this adventure and share their ideas - the suggestion here are not only great for fellow GMs but for freelancers looking at approaches in the future.