It's hard to betray family, so I can see a reason for Jaime to go back to King's Landing for Cersei. It just seems so sudden to go from an intimate knighting of Brienne to saying **** it I'm going back to Cersei in less than 2 episodes. I agree, Dany and Grey Worm turning into cold blooded killers of innocent people is more troubling. Sure, there was some foreshadowing that Dany was going to become Queen of Ashes, but it still felt sudden.