I really hope the Duke is a minor villain. He wants to exploit Arendelle's tradable goods.He obvs talking about ice.But it's still a wierd motive.It's not like Arendelle exports ice under cruel intentions in the first plave.In fact, the sami people (including Kristoff) have no problem harvesting ice..What if the ice trading actually helps Arendelle during Elsa's abscence?This makes the Duke look like the bastard of an anti-industrialization activist and Ratcliffe.(Which is a wierd combination of egg and sperm)
As for Elsa,I think it would be really cute if she had this Victoria/Albert relationship with Hans. Hans will do something,and Elsa would take it the wrong way and say,"You made me look like an idiot!I am the queen!And I must look powerful!".Hans would reply,"I'm sworry."The next day,Hans does something to show his protection and love.Elsa apologies ,and they kiss.It would be so cute! ^.^
That would be perfect. And it would be so right for their characters. It makes me smile just thinking about it.
She feels alone because she isn't with her family and/or she doesn't feel accepted by them. At the end, she'll have both. I wouldn't call that "alone." I don't think it would ruin the film, and I doubt most viewers would care enough to walk out. But I could be wrong, since I've never walked out of a film before just for the simple fact that I paid for it. 
