Originally I thought that Daniel being brought back would mean he would be around in Storybrooke for longer, actually BEING a monster and being a serious threat to everyone. Instead, he’s taken care of in one episode.
If Regina was really letting Daniel go, then the natural thing for this episode would have been for her to pull his heart out. Instead, she made him vanish. Possibly transported instead of dissolved? At the end, she seemed to be admitting not just to using magic but to using it for selfish reasons.