To avoid Slynt undermining his authority with his scheming, to separate him from his ally, Alliser Thorne, and in view of his experience, Jon Snow, now Lord. Across the sea, Dany pays a terrible price for her love, but finds new hope. Looked over the town of Vik. Meanwhile Mormont never returned due to a mutiny at Craster's. But then she can't because she loves him too much.
Sansa Stark. There is no waterfall, for example. I could watch their reunion on loop, it's that nice to see. Catelyn Stark hated him with the passion of a thousand suns.