Oh, come on, guys, this is Disney we're talking about here.
For a movie this romantic, it's incredibly chaste. The violence is implied (we don't get to see the no-doubt satisfying moment when Gaston hits the bottom of that ravine), and the curse words don't venture much past the "oh, phooey" stage. This is as family friendly as you can get, delivered by the one studio in Hollywood that can genuinely ask you to trust them with your kids.
But, like a lot of animated features of the era, it's intended for adults as well as children. That means they can slip some very interesting stuff under the surface. Look at the seriously threatening way that Gaston menaces Belle when proposing to her, for example. Or, the terrifying way he manipulates the villagers' surprise and fear into a torch-bearing mob. Like a lot of Disney's best films, there's a fair amount of darkness swimming around here. The G rating can't hide it from discerning viewers who know what to look for.