There is an episode in which a a young girl is hitchhiking and is picked up by a stranger in his car. He kidnaps her, and the implication was that he was going to rape her or sexually abuse her in some way.

One of the main characters is a scantily-clad Amazon female who shows her cleavage throughout. Other barely dressed characters appear throughout, usually in bikinis or other costumes that showed a lot of skin.

The violence was very mild, although it was a step up from the 1973 series. There were scenes in which the entire Earth was in peril, even scenes in which entire planets were going to collide, and Superman couldn't stop it. But no on-screen death or blood, punching etc.

There is an episode where a girl is kidnapped, and although it is never stated, it seems pretty clear that the kidnapper intends to do something violent to her, probably rape.

One episode shows violent teenagers vandalizing a school and setting it on fire.

Only minor religious euphemisms.

There was a reference to alcohol, drugs and smoking in some episodes of the show, but they were always presented in a negative light. On a couple of instances they were discussed in PSAs.

Very small children might find some of the monsters in this show somewhat scary, such as the Plant Creatures.