Belle has always been an idealist, and I think that’s the thing they’ve most consistently characterized her with. It comes out in her insecurities as we saw in Family Business–she’s so hard on herself for having let Anna fall that she can’t even believe Rumplestiltskin could understand what she did. She idolizes her mother’s heroism and the characteristics of the heroes from her stories are, to her, attainable traits for everyone. That’s part of why she’s able to see the best in others, because she believes it can be there, but it also makes it hard for her to accept anything less than her ideals from herself or those she loves.
It’s also why it’s hard for her to accept that she loves Rumple in part because of his flaws, that she is attracted to his dark side as well as his inner goodness. It’s not what you’re SUPPOSED to like, so it winds up being a “failing” of hers instead of just how it is, you know, reality. Sometimes she can see it (it’s easier in the abstract, when he’s not there, when she’s missing him), but other times she struggles with it because it flies in the face of the standards she holds herself, and him, to.
Her ultimatums come from this idealism, as well as her anxieties. And I don’t think she was proved wrong, but it’s easy to see how she would immediately jump to despair over what she did to Gaston. It was exactly the thing she was trying to prevent; while her defensive move to stop Gaston’s attack was entirely justifiable, she never meant to doom him to an eternity of being lost. For an idealist, middle ground is hard to see. It’s all or nothing, especially in the worst moments…
But this does go along with what I was saying last week about how both Rumple and Belle are going to have to compromise. We aren’t quite yet seeing it from his side, but maybe this will help Belle come to terms with a reality that just won’t fit her idealism–though I hope she doesn’t lose it entirely. That is, as someone said, what makes her a flicker of light; it gives her the ability to be heroic and optimistic and see the best in people. She needs to temper it with the ability to accept that not everything can be perfect.
Rumple meanwhile needs to find a way to be the better man he keeps promising her, someone she can be with without compromising her core principles (murder is bad is a pretty good start, and he’s obviously not there yet).
Keeper of Belle's Gold magic, sand dollar, cloaks, purple FTL outfit, spell scroll, library key, copy of Romeo and Juliet, and cry-muffling pillow, Rumple's doll, overcoat, and strength, and The Timeline. My spreadsheet: https://drive.google.com/file/d/0B6r8CySCCWd9R0RUNm4xR3RhMEU/view?usp=sharing