I like the books, but to get my group to hate Harrigan I had the following thoughts.
The starting premise is that the party will own a shipping company that can expect to be attacked by pirates. (thus the info in the Players Companion is still helpful).
As newly formed shipping company, they had the ship Wormwood commissioned. (I am going to let them modify it a bit so they feel a connection to it.) I plan to have them actually build a playmobil ship that I found on craiglist.
To start the adventure, Harrigan's fleet attacks them on their maiden voyage. Steals the Wormwood and strands them on a deserted island for a week+.
Harrigan returns to press gang them into service in return for rescuing them. (start the Mutiny part 1).
Then after they take the Man's Promise (and are headed to Squib's refitting) they are captured by Chelish authorities and put on trial for piracy for being in possession of the Promise. (Harrigan will somehow be involved in them getting convicted.) After they are convicted and labeled pirates (so they can not return to the shipping company), they are to be hanged.
I plan to have Sandra give some of the party a potion that will ease the pain of hanging and allow her to save them after they "died". At this point, they have to become true criminals. Once they escape on the Promise, I will continue with the books.
To me, stealing your ship, getting you hanged and turning you into a pirate seems like good reasons to hate Harrigan.
I am looking for guidance from those who have run this before. Is this plausible. What could I do to fit this concept into the book structure better.