My take on it… and I’ll add a trigger alert with it because I’m sure someone, somewhere will be offended. Please remember–it’s an opinion and it’s not a personal attack on anyone.
Don’t use the *** censorship. It’s ridiculous, in my humble opinion. Either use the word you think should be censored or don’t. Censoring like that is unprofessional (far more unprofessional than just saying the word) and childish. Which may be fine if you’re aiming for a teenie bopper crowd.
Personally, I not only have zero problem with cursing, I typically find it more “real” when characters (some of them, anyway) do curse. People curse, it’s a fact of life. Some people don’t, and that’s also a fact of life. Since characters are meant to be as “real” as possible in order to draw people into a story, it makes sense that you’d have some of both types in a story. Well, unless it’s set in some overly strict society where people are ostracized, attacked, and/or murdered in cold blood for using “wrong speak” (which, honestly, I’d love to read a story like that, especially one where someone decides some innocuous word like “is” is horrible and that causes an uproar, because it reflects so well on today’s sometimes overly-sensitive atmosphere).
That said, if you use the dreaded “bad language,” you will likely get some people who refuse to read it, get triggered, and throw tantrums over it. But if your story is aimed toward adults, that really shouldn’t be a problem because adults tend to deal better with controversial and mature things like “coarse” language better than the younger crowd.
The bottom line is that–and this is something I’ve learned over the time I’ve spent on the COG discussion boards–you’re going to have someone offended over something in your story, even if it’s one person or a small group. So, probably the best advice anyone can give is to try to find a balance between your vision and presenting it in a way that offends a smaller group of people. And I think cursing is not a big deal to the majority of people. If some or all of your characters curse, they curse–I think there are enough people who are fine with that or will read it anyway. There’s no need to force your characters to be someone they aren’t just to appease people who don’t like a few supposedly “bad” words.
Edited to add:
The best way I’ve seen of dealing with this for the MC, and it’s a way that makes the IF more personalized, was the way @Morgan_V handled it–she put in an option at the beginning so the MC could declare their own “curse” word. One of mine drops the f-bomb, while another says ‘poo!’. It fits their characters perfectly, and it’s used in the appropriate places. Really, I think that’s the thing you should focus on most–letting the words fit the MC–rather than letting reader preference guide NPCs that you developed and know better.