Great topic! I agree that the various facets of R/G’s character are most intriguing. So here’s my two cents (and worth just about that!)………
You may be over-thinking the Rumpel/Belle breakup, so to speak. Think about any time you have been in love, or thought you were in love, or wanted somebody to be in love with you. The prospect is kind of terrifying in one way, because to love somebody is to make yourself vulnerable. Often the more bad experiences you have, the less willing you are to take that risk again. We know that Rumpel’s wife left him because he was deemed a coward (although running away from ogres just sounds like good sense to me…..but that’s for another thread). We know he lost his son, somehow, presumably as a result of becoming the dark one, or in any case, something that Rumpel himself did.
We also know that Rumpel is pretty much a total social outcast, feared and hated by society, and approached only when they want something from him. Cinderella makes a comment about previous efforts to imprison him, making it sound like there has been an ongoing effort to lock him up or strip him of his power. One thing I heard, and I will put a spoiler tag on it because it was other than canon —- I think this was tweeted by the writer of “Skin Deep” with regard to Rumpel’s history: Hundreds of years have passed from the time Rumpel became the dark one to the time he meets Belle. The ogre war they refer to is not the same war that Bae was being recruited for. So Rumpel has had a long time to be alone and get a little emotionally warped.
Soooooo….. Rumpel is clearly perpexed by Belle’s treatment of him, that she treats him like a person and not a monster, so he lets his guard down around her. He lets her go, telling her that he fully expects she will never come back, but as we see, secretly hoping she will come back to him. So his heart is pretty much laid wide open when she kisses him, and he kisses her back. So then what does she say? “I love you”? “You are my soulmate”? “Carry me to your chamber and….” well you get the idea. No. She says, “It’s working.” 😯 Seriously? It’s working? No wonder Rumpel assumed (correctly) that she had an agenda. That she kissed him not because she cared about him or was attracted to him or wanted to be close to him. But that she was trying to accomplish something.
Then when Belle mentions “she,” Rumpel’s thought immediately goes to the Queen, with whom he is evidently feuding. (Lots more to learn about that relationship!) That he assumes Belle’s motives are somehow to hurt him I think is a result of his history, of never really having been loved.
Okay, that was longer than I intended it. More to say about his post-banishment regrets, but I’ll come back to that later. One last thought on his bad reaction is that we can never forget the Dark Curse itself. Belle says that “evil has taken root in him,” and we see the change in Rumpel even immediately after he is cursed. I see it a little like the One Ring. No matter how you intend to use the power, it will consume you and corrupt you.