Bruce wasn't use to someone flirting with him. Though, he wasn't bound to flirt back when he was seeing someone. That doesn't mean he doesn't give River a bit of a smile," Why haven't you quite made it? Too much going on in your life?" Isn't that how it normally goes? Things happen in life and a person misses out on certain things.
As for looser settings it was something she'd have to ask about. Or let him know that she wanted a bit more danger in her life. It was one of the reasons he liked the holodeck himself.