Brings up issues of loyalty and friendship. Also explores the idea of personal will vs. the collective good and hones in on the fact that people who are wrong but think they're right can be the most dangerous kinds of adversaries. Focuses on the necessity of trust between teammates and how keeping something secret can be thought of as lying to someone. Characters demonstrate courage, integrity, and teamwork.
Avengers fight with outside forces and against one another. The fights usually involve their enhanced artifacts (like Cap's shield, Bucky's metal hand, and special suits), but the adversaries use weapons. A character grieves the death of a loved one. Explosions, guns, and enhanced weapons are used. Tons of explosions, collateral damage, and innocent casualties -- including a couple in more close-up than is typical for these films, which makes the impact more upsetting. An intense violent act from someone's past is revealed and shown.
Cap shares a quick kiss with a woman. Vision and Scarlet Witch exchange a couple of longing looks and embrace a couple of times.
A couple of uses of words including "s--t," "son of a bitch," "ass," "hell, "damn," "oh my God," "goddamn," and more.
Nothing overt in the movie, but there are many, many Avengers-related toys, action figures, games, apparel, and other products associated with all the characters in the franchise.