"Change means that what was before wasn't perfect. People want things to be better." Esther Dyson
Through years of fiction writing, I've learned if you are willing to change something in a story then it needs to be changed. Take character names. If you're willing, without hesitation, to change a character's name than the name isn't a right fit. But if you reach a point where you can't change the name without possibly changing the character or even the story then that might be the right name. The name and the character should speak to each other.
I'm currently rereading one of my novels, unpublished. I'd left it in first person for some time now but recently, I've been toying with the idea of changing it to third. I hesitated simply because of the amount of extra work involved. But now that I'm changing it, I'm finding the story reads much better.