Just to comment on your post I'll leave it in a spoiler tag for now.
That doesn't surprise me because doesn't Thor end up with Sif in the comics even though I know for awhile he was infactuated with Jane Foster for awhile? I could be wrong though. That or they are using that angle to write off Jane Foster so in the third one it isn't something they have to focus on a bit more?
It wouldn't surprise me if it is the actress playing Jocasta. I'm not sure about the comics (never got that far), but I know in the Earth's Mightiest Hero's that Ultron wanted to create Jocasta by using a human body/brain (think it was more brain like how his was Pym, guessing Tony in this one?) in order to create him a partner.