well your friend isnt wrong. Bilgewater is filled to the brim with criminals who will gladly slice you to pieces, is subject to the Harrowing annually (could be wrong on that), home to MANY sea monsters, and the only upside is getting rich quick if lucky. and that last part does not even matter due to just becoming another target for people to kill for your money. Ph and if you have a dumb captain who does not pay the tithes, well good luck, you will likely die.
basically, you have to be tough and at the top of your game constantly. Gangplank lived his life paranoid (but luckily not consumed by it) as the boss of all Bilgewater. the only place (obviously not including places like void or shadow isles) I would say is just as if not more dangerous is Zaun
EDIT: oh yeah, also watch out for the Blood Harbor Ripper.