1. Not much actually happened. I mean, in the sense that the sum total of the plot was Jon goes to see Daenarys, kills her, then everything gets resolved in deus ex machina fashion reminiscent of that Moliére play. I wish there had been more events occurring before the meeting between leaders of the land, because that part felt a bit empty.
2. Some things didn't make sense. Jon should not have been allowed to speak to Tyrion alone for so long, should not have been allowed to meet Daenarys without supervision, and should definitely have been charbroiled by the dragon after killing her.
The peace conference or whatever you want to call it was probably the weakest part of the episode.
It made no sense for Tyrion and Jon to even still be alive (Grey Worm ought to have killed them), nor did it make sense for Tyrion to be allowed to speak. And it gets ridiculous when he is allowed to pontificate, and appoints Bran of all people (there's no logic to his argument. You might as well appoint some random peasant.) It seems out of character for the leaders to agree, too. And far as I can tell Grey Worm went from the table with none of his demands met.
3. After that, things get better. I liked how they wrapped up the fates of the main characters. I don't really get why Arya would suddenly choose to go exploring the sea (does she know much about sailing?). Thought maybe she could have gotten a more interesting ending. But whatever, maybe there have been prolepses in earlier seasons to make her ending more of a payoff, and I just don't remember them. Half expected her to go all lesbian and explore the seas with Theons sister though.
I didn't quite understand what happened to Jon in the very end. Did he leave the Nights Watch to go live with the Wildlings? Or was the expedition beyond the wall at the end just a Nights Watch mission?