The Duke represents Christianity because he condemns Elsa for sorcery. Sorcery is a sin in the Bible. I also think it is possible for the filmmakers to be portraying deep love between the sisters, but the people who support Elsanna are too strong.
Nope, a character condemning sorcery does not mean that character is “representing Christianity”. The Yuuzhan Vong in the Star Wars EU stories considered the Jedi to be sorcerers, and the Force to be magic, but they followed a very disturbing religion based on self mutilation and the sacrifice of sentient beings.
And in the ASOIAF books, the Dothraki also hate and despise sorcery and magic in the ASOAIF books, but I really hope you don’t think running around raping and pillaging is a Christian thing to do. The “maesters” also despise magic in that universe, but they don’t represent Christianity either. Indeed, I could make a case that they are actually representing secular humanism.
Also, the Duke doesn’t mention Christianity at all and while he does accuse Elsa of “sorcery”, he never actually calls her a witch. He does call her a “monster” and I think his reactions are based on fear, not piety. I also don’t see Elsa’s magic as the kind that involves demonic activity, unless you think ALL Disney magic is based on demonic activity. I guess you’re not a fan of Sofia the First, a princess of “Enchancia” where magic is a fairly humdrum part of everyday life, either.
To me, and probably most people reading this, fantasy magic =/= witchcraft. But if you don’t accept that, then further dialogue is pointless, I suppose.
All that being said, I did get the sense that both the Duke and Hans actually did see themselves as morally superior to Elsa, and justified in their attempts to destroy her. And this kind of attitude, that “obviously that woman is a monster and I’m just a man trying to get ahead in the world” certainly reminds me of SOME who claim to be Christian. But not the type of Christian I’d want to identify with.
As for “Elsanna” shippers, as I pointed out before, creepy shippers are unfortunately part of most fandoms, but apparently you’re not going to change your mind on this, so I’m not going to repeat myself.
Let me discuss good ol’ Olaf, too. Unlike most other Disney movies, he wasn’t just a cutesy sidekick gratuitously thrown in to appeal to the kiddies. I actually thought it brilliant that Olaf is shown at the beginning of the movie as an inanimate snowman built by the sisters the old-fashioned way (only the snow is magically created). When he is re-created by Elsa, he seems to embody her yearning to return to the innocent days of her youth. And by having the innocent and naïve Olaf, who speaks the most profound truths about love in the movie, actually reminded me of the idea that a “child will lead them” and has an innate understanding of such things.