Piracy is all about freedom, to capture the most possible freedom the player should get the choice. You've provided that choice, as well as giving a warning that there is an option to turn brothels on/off. I'm not sure I understand why you care that people who download your mod of their own free will might be offended and not play it. The only threat they pose to you is that they might demand further changes that could possibly alienate the people who love your mod as is. The poll response shows that most of your players like or don't mind the brothels. The world's second best rapper once made the point that in a free society, the only people that we should be offended by are those that take offense with people different from them and attempt by force to change their behavior and beliefs.
Now this option I found it interesting nobody brought up the point so far. If you want to be politically correct, there should also be male courtesans because you've got female main characters, and I'm sure there were gay pirates, too. And it's not fair to exclude the majority (female + gay population is greater than number of straight males) of the world's population the opportunity to indulge in their pirate fantasies. How about Johnny and Orlando's stunt doubles?
As far as what I would do, it's not really listed so I went with as is. Instead the choice of brothels or no brothels, I'd make it bare bones Brothel, where there is no sex or innuendo, instead you have things things like a Masseuse and preening services(cleaning and grooming so your pirate's outfit is spotless and he is well-shaven etc) I guess those services could be acceptable, and then of course all the quest npcs that are needed will be there, so there wouldn't be a chance that a player would try Assassin without brothel on and then get mad and give up, thinking there's bugs in your mod.
Then you have the FULL brothel option, where you can be free to put in all the "Interesting" features that you're worried about people being offended by. I found them to be overrated, even disadvantageous. Pay money to lose 1 game day, that's what it is hehe. But I will admit I was laughing at a lot of the dialog. Surely your crew would like to indulge also, so perhaps your purchases in the salon should have a boost to crew moral, but of course the bill of services for a full Frigate crew would be mighty expensive. Not sure if it's possible, I don't really care if it were added, but it was fun for me to write an extensive response to your poll.