Bran is watching (caws in the background of every LF scene).

Arya giving the dagger to Sansa might be code.

Honestly I don't have much opinion on the Sansa/Arya thing since I have hate the scenes so much I've been skipping them on rewatch. I just really fucking hope that Arya doesn't wear LF's face after he dies in order to keep the Vale around. Love the Faceless Men assassin thing but hate the face changing.