It's alright. There's a lot of cartoonish violence in it, like Looney Tunes; bombs, dynamite, guns, etc. As for sex, well, I'm guessing they're some male characters flirting with the female characters because of their figure. As for drinking/drugs, there was smoking as it was popular during that time. This stuff may go over kids' head.
I love this show. It's definitely safe for kids. It was on Nickelodeon when I first saw it and it was rated TV-Y (could have been TV-G but I think TV-Y) and I didn't have a clue what it was about. Note I was 5. I loved it. It was hilarious and adorable. Let your kids watch this show if they're at least 5.