Powerful message of friendship among the Hobbits and the other allies (including different species). The seemingly meek Hobbits earn Middle-Earth-wide respect through battle and heroism. Theme throughout of sacrifice made in an immense struggle, including fighting against presumably impossible odds and overwhelming numbers, and trying to be brave against inevitable death. Additional themes include courage, perseverance, and teamwork.
Violence is savage and intense for a PG-13. Thousands of creatures and humans are speared, slashed, hit fatally with arrows, crushed, decapitated, impaled on large spikes, and in the opening scene, painfully strangled to death. There's a catapult-shower of severed human heads, venom-stings from a monster spider, and characters burning to death. A key character's finger is bitten off.
Hard to ignore the original Tolkien books, not to mention a plethora of video games, movie tie-in action figures, role-playing games, plus the movie sequels and other existing adaptations.
Drinking, Drugs & Smoking
Joyous drinking to the point of inebriation in a celebration. Pipe smoking.