The movie raises issues of trust, warning us that no one is to be trusted. The downside of that is that when people do tell the truth, nobody believes them. A title card before the opening credits talks about problems with discrimination against immigrants; even though the movie does a fairly poor job of offering a message on that topic, at least the title card offers something to think about.
Guns and shooting. Blood spurts. Bloody, gory wounds. Dead bodies. Car crashes. Small girl killed in car crash; she's seen lying on pavement. Character hit in the head with a frying pan. Intense flashback/nightmare sequences. Other disturbing imagery.
A use of "f--kin'," a use of "goddamn."
Main character pops fistfuls of various prescription drugs, described as "psychotics" (but really anti-psychotics?). Adult characters drink beer socially.