Frozen (Disney film)/WMG

Hans has no personality of his own, but rather reflects the people he is around.
As explained here

Anna is lesbian.
While Anna may appear to have male love interests this is in fact not the case at all.

Hans reflects whoever he is with, which means Anna was attracted to her reflection. Since reflections maintain the gender of the reflected person, Hans is female for Anna.

Kristoff is based on The Robber Girl who is female.

If Anna had actually died, Elsa's blizzard would have expanded into space.
Either due to her fear of her powers becoming that much stronger, or because of her murder being akin to breaking open a floodgate.

Elsa is a Magical Girl
She even has a Transformation Sequence.

Anna planned to murder Hans and claim the throne of the Southern Isles for herself.
Anna's love for Hans was just as fake as his love for her, she just never got the chance to enact her plans.

Kai and Gerda are the same Kai and Gerda from the original Snow Queen stories.
It could very well be that they decided to serve the Royal Court of Arendelle at some point in their lives, having been happily married and moved from their home kingdom of Snoob where Kai's brother still lives. It so turned out that history sort of repeated itself and a new Snow Queen emerged in the form of Elsa.