I'm really not very sure about either of these characters (or about anything in socionics as my sig may point to). But I would possibly disagree with Belle as being "outgoing". She may seem so when she going through the town singing (but she has to do this because she's a Disney cartoon character), but it's more her own private song to herself. Her trip through the town is to go to the library so she can get more reading materials, as apparently she spends most of her time "with her nose in a book" and although the town's people pay a huge amount of attention to her because they think she's odd and that her behavior just isn't right (i.e. her behavior of ignoring all of them and all of their customs and burying her head in books all day before returning home to her overly weird father where I assume she spends most of her time), I wouldn't say she's "popular" with them, at least not in a good way where they all adore her. They all notice her because she's weird to them (either they dislike her for being so, are jealous of her because of her looks, or in the case of Gaston see her as something that outshines the others to possess probably because of how she doesn't come off as approachable since she's always ignoring the towns people and often some of the things going on around her--I mean Gaston had to take her book from her and throw it in a mud puddle to finally get her full attention--he sees her as a challenge since she's the only girl in town who doesn't pay any attention to him).
Of course Belle also seems rather initiative-taking I suppose. She's just waiting for something to happen to give her an excuse to leave the "provincial little town." And she's frequently exclaiming things rather enthusiastically.
I'm thinking about this more.