We decided that our 9 y/o should finally see this. We was scared going in and covered his eyes during some of the more intense scenes, but in the end he thought it was good. He's been a fan of Danny Elfman (Tim Burton film) soundtracks for years now: specifically Batman.
The Maitlins are great role models. They express affection, they choose to work on their house during their vacation, they pay attention to details, they respect each others opinions. It's easy to like them and understand their choices.
It's hard to like the Deetses. They are by turns bullying, passive-agressive, sarcastic, greedy, petty, enabling, etc.
The language rules for PG were a little more lax during the 80's, be aware that Beetlejuice lets out an F-bomb.
There are several characters who smoke cigarettes, including one at the dinner table.
It's pretty heavy material: death, suicide, the gentrification of Connecticut...
The music and absurdity of visual effects help soften the scare factor, and Beetlejuice is a wonderful dark clown.