Not that I'm questioning your assessments, just the brains of the showrunners for stalling two major characters if they only have three more seasons to wrap up 2-3 books worth of character arc.
Official synopsis (last one available): Dany balances justice and mercy. Jaime tasks Brienne with his honor. Jon secures volunteers while Bran, Jojen, Meera and Hodor stumble on shelter.
Daenerys chooses what to do about Meereen, and may even take the city before the episode is over. Jaime gives Oathkeeper to Brienne and dispatches her to find Arya.
It was Sansa in the books. If this is two episodes after Joffrey's death, she'd be gone on the show too, so there is no reason to change the mission for Brienne. As for the justice and mercy thing with Dany, I'd say that could also be in regards to Jorah. Or maybe they're going not going to exile him, since he comes right back later on. They could keep him to voice the conflicts she has throughout her arc of ruling Meereen, as a contrast between Daario's impulse gratification and Selmy's honor and duty mentalities.
Either 1) Littlefinger helps Sansa escape (she doesn't escape when she does in the book, as she's present at Tyrion's trial) or 2) Sansa escaped an episode or so earlier and arrives in the Vale this ep. We possibly even get Lysa and Petyr's marriage in this episode.
Big season finale. Likely Tywin's death, Tyrion's escape and Jon's election as Lord Commander. Possibly Lysa's death as well. Final shot: either Arya seeing the (already-established) Titan of Braavos appearing on the horizon, or UnCat revealing herself (possibly to Brienne rather than as in ASoS).
Things that will happen, but we just don't know exactly when:
Ygritte and Tormund's raiders attacking villages near the Wall. Their attack on Castle Black, although some rumours say their raid from the south happens simultaneously with Mance's attack from the north in Episode 409 (which makes a lot more sense than in the book).
Team Bran run into the Night's Watch traitors at Craster's Keep. It's unclear if this is a narrow miss or they are captured. It is known that Jon attacks and wipes them out, and presumably Team Bran escape before this. A Jon/Bran meeting seems unlikely. Team Bran reach the cave of the Three-Eyed Crow before the end of the season, but when is unknown.
Daenerys takes Meereen, resolves to stay and do justice and is presented with the bones of the child Drogon eats. Daenerys meets Hizdahr, but does not appear to have decided to marry him yet. More intriguingly, Ser Jorah is still with her when the bones of the child are presented. It is possible that the discovery of Jorah's betrayal is delayed to provide a cliffhanger where Dany's storyline doesn't really have one (since it seems to go at least a little way into ADWD before concluding).
Stannis and Davos visit Braavos and win the support of the Iron Bank; this is an ADWD storyline, but done in Braavos rather than in the snows outside Winterfell, and before the attack on the wildlings rather than afterwards.
Brienne's storyline is up in the air. It may be she only completes part of her AFFC storyline, or it is cut down and she does all of it and is hanged by UnCat in the final episode.
Or maybe this is a hint that their time is limited in the books, and the golden twins bow out before the final act.
“Tolerance is the virtue of the man without convictions.” GK Chesteron
Inde muagdhe Aes Sedai misain ye!
Deus Vult!
*MySmiley*