StarMan No on-page sex. A few curse words. No religion. Vague politics. A bit milder than expected, in spite of fictional violence. I'd say safe enough for most readers age 12+, who've seen stuff far worse on the Net or TV.
sh(e)reader It really doesn't have much - I was listening as an audiobook, and at times had my 10year old in the car with me. There was some mild profanity in some parts. At one point sex is mentioned as a possibility (after a couple has been life-partnered) but nothing graphic at all.