There's lots of not-so-subtle commentary on war and government, as well as some practical joking that some would consider cruel or sexist, but at its heart, M*A*S*H* is about holding on to your humanity in the direst of circumstances. Themes include communication, compassion, perseverance, teamwork, and empathy.
Wounded, bloody soldiers writhe in pain in the operating room and in recovery. Occasional gunshots. Some slapstick punching and hitting.
Some kissing and groping, usually comedically. Hawkeye is always trying to woo the nurses. Subtle allusions to casual sex. Jokes about female body parts. Klinger cross-dresses, but it's almost always played for laughs.
Occasional "hell" or "damn."
Radar loves Grape NeHi soda.
Drinking, Drugs & Smoking
The main characters have a homemade alcohol distillery in their tent, and they drink martinis regularly.