I enjoyed the book, as a 15 year old, but it is a "young adult" book, which, in my understanding means that it's geared towards teenagers. In my personal opinion, since teenagers are at least in middle school, they probably experience swearing on a daily basis at school, and are aware of what sex is. It depends on the maturity level of the person, but I there's nothing "new" that your TEEN shouldn't know about in the book.
Personally, I don't really find an issue with swearing in young adult books, because it's more realistic than if the teen characters went around saying "gee-darnit!" or something like that. The book does follow a High School student, and thus has high school level situations along with it.
The only reason that I give it a bad rating for role models, is because the main character is involved with Damen, who you learn is actually around 300+ years old, even though he is a teens body. I think that this sends a message about the way people look (similar to the Twilight Series). We all know that Ever wouldn't be attracted to him if he had the body of an old man, but just because he appears to be her age, it's okay.
Overall, though, a good read that also has some psychic and supernatural undertones that are enjoyable!