Where is the red witch right now? My guess she is going to do something in the war, that brings that dragon back. Also there was another red witch with Dany in the previous season, where is she? I don't think we see anymore main characters dying this season, maybe littlefinger and Grayjoys sister, for the simple fact that 1 or 2 may be killed off in each of the 6 episodes next season.

I think Arya realized she's been played by littlefinger. That's why she didn't kill Sansa when she easily could have.