Common Sense Note
Parents need to know that Wrath of Khan is a more violent feature than the original Star Trek: The Motion Picture, with assorted character deaths and torture. One of the biggest stars of the series dies. While the TV Captain Kirk always seemed to have girlfriends on every planet, this is the first time it's acknowledged that one of them bore him a now-adult son, and their paternal relationship is not close or cordial.
We learn that Kirk has an illegitimate son by an old lover, and she describes the Starfleet hero as "no Boy Scout." Kirk eyes a pretty Vulcan, but that's as serious as it gets.
Phaser and photon-torpedo battles, with deaths (including major characters in the series). Two men are tortured in gruesome detail with brain-burrowing insect-like parasites put into their ears. Scenes of corpses after a massacre.
"Hell," and various forms of "dammit" from Dr. McCoy especially.
There's a continuing theme throughout about how to react with courage and resourcefulness in a seemingly hopeless situation.
Star Trek is an enormous commodity with plenty of merchandise available to buy.
Drugs / Tobacco /
Social drinking, with Dr. McCoy bringing Kirk some "old" (22nd century) wine for his birthday.