taei wrote:Spoiler speculation zone:
I think that the duke wanted to use Elsa's power for evil. My best guess is that he was the one who cursed Elsa to use her powers. She realized what he was doing and runs away because no one believes her. 
Something like that. I am 95% sure that it was the duke who was telling her to control her powers. 
I really hope Elsa is over 21, we havent had an adult character in a while, and it'd be really interesting to see an older princess. Right now, I'd say Belle is the oldest, they never mention her age..
But,but,but,but,but,but-I thought Elsa had these powers by birth?And what the hell does Hans do?
Well,okay.Here's my cheesy theory split into two forms
1.The Duke is not evil: Elsa and Hans had a a very intimate relationship:therefore,at some point Elsa reveals his secret to Hans. Hans doesn't want to be associated with the possible prophesized evil monarch and breaks up with her.Years later, Hans dates Anna because she's the closest thing to Elsa. All of this enhances Elsa's anxieties.After Elsa's powers are revealed and she has retreated to the ice castle,Hans feels guilty about what he had done in the past and tells Anna to search for her (because he is too much of a pussy to apologize face-to-face by himself.  

 )Anna leaves Hans in charge,but he has NO f-ing idea what to do about a frozen kingdom.At one point he ready to give up,and let the people take matters into their own hands( even letting them execute Elsa).
 The Duke takes the role of an advisor and uncle who apparently doesn't like Hans because Hans can easily take a piece of Elsa and Anna.
 The problem with this plot is that Hans giving up on the monarchy system is not really considered "cold hearted" (unless the people execute Elsa).The directors would also have to make up time to illustrate Elsa and Hans relationship whether Hans truly loved her or not.
2.The Duke is evil: The Duke takes note of Elsa,Hans,and Anna's weaknesses and uses them to advantage of destroying their positions. Elsa has wierd powers that fit her into the prophecy.Hans is unwilling to accept Elsa or apologies face-to-face.(Yeah,this makes Hans a shitty match for the princesses.) And Anna can possibly screw this up if she dies on the mission to find Elsa or if she cannot convince Elsa that she is still good-hearted.
This version actually sounds pretty realistic.It gives an interesting touch.There is also historical evidence that the young monarchs where taken advantage by court members who wanted the throne or wanted to destroy the monarchy.
Yeah these theories are pretty wierd 

 ,but I don't know what to make of it.There's not much official material released by Disney right now.