Common Sense Note
Parents need to know that the movie breaks no new ground content-wise (except for showing Bart's tush and penis). The same hilarious -- but intentionally in-your-face -- levels of humor apply. The movie features a few more edgy words and sight gags, but nothing comes near, say, South Park levels. Minor characters and animals are crushed, kicked, and killed off, sometimes in groan-inducing ways. Bart gets drunk, Marge and Homer share a pre-coital scene, and there are lots of jokes that reference other movies and cultural events that might go over the younger audience members' heads.
Bart skateboards naked -- his butt showing and a momentary penis shot. Homer and Marge get into bed mostly undressed to make love (no nudity is shown).
Besides the many painful gags involving Homer, a couple minor characters die (two are smushed); a robot commits suicide; mobsters haul a dead body in a rug; an angry mob tries to lynch the Simpsons; and Homer, as always, strangles Bart.
For the most part, same as any episode: "ass," "hell," "dammit," "cojones," "crap," "god--m," "screw"
Homer has an epiphany that other people's feelings, especially his family's, are just as important as his own. He acts selflessly for the first time, well, ever.
Just well known fictional Springfield brands like Buzz cola, Duff beer, the Kwik-E-Mart, Krusty burgers, etc. Green Day and their song "American Idiot" are spotlighted.
Drugs / Tobacco /
Bart drinks an entire mini bottle of whiskey; Otto smokes a bong; Homer and his bar mates drink beer at Moe's (and other places as well).