We don't know if Barristan and Grey Worm are dead -- it's entirely possible one or both of them will recover. Grey Worm is technically expendable, since he doesn't do much in the books, but they also talked about more romance with Missandei this season. So he has a good chance of surviving. Barristan should technically live since he has more stuff going on in the books, but if he dies in the show, that might indicate he'll kick the bucket in the next book. Worrisome. I like Ser Grandpa.
The politics of Meereen are interesting. I'm not sure how this will all play out, given the changes. Daario might take over for Barristan.
As for "Cleganebowl," I saw some rumors that it would actually be Brienne who ends up fighting Gregor. But I don't know how that will come to pass, either. I don't know why the High Septon would ever choose her for a champion. Sandor would make more sense if the Gravedigger theory is true (and it makes for a good wrestling name), since he'd technically be affiliated with the Faith. But none of that has been hinted at on the show yet.
Sansa.... oh, poor Sansa. Can't ever catch a break. I sincerely hope that she avoids Jeyne's fate, since it would be almost unbearable to watch. She did mention that "traumatic scene," though. Just... ugh. I double checked the first trailer, since Ramsay was seen screwing someone. Fortunately, it's only one of his sex-wenches. Not Sansa. With the new plot setup, Stannis might sweep in and name Sansa the Lady of Winterfell. The "complicating factors" of ADWD's Winterfell storyline aren't present in the show, so things should go much smoother for Stannis in the show. But then again, Sansa has the worst luck in the universe.
Either way, if she ever finds out that Littlefinger was largely responsible for getting Ned executed, she is gonna lose her fuckin' shit. And if she's got the Northern lords on her side, then that shit-losing will be even more awesome.
I don't like how they're handling Loras, though. He's kind of turned into the token gay. He's lost almost all of book!Loras' good traits. He's not in the kingsguard, he's not marching off to war, he's not heartbroken about Renly, he's not the sullen-but-passionate dude who argues with Jaime and earns the childlike admiration of Tommen. And the Faith Militant never seemingly cared about sexual orientation in the books, so that's... an odd adaptation. The show writers have never been very respectful of the LGBT characters in the series, even back when Renly was alive. They lose most of the traits that made them interesting characters -- characters who weren't defined by their gayness. It's disappointing.
Tyrion and Varys scenes are always good fun, though I wonder how long Varys will stay in Essos -- since he has a very important meeting in Westeros later on. But I'm thinking they might not even go that route in the show, given the lack of Aegon.
It also doesn't seem like they're doing the Sam Goes to Oldtown storyline, in which case... hmm. Unless they do this later on. They're rushing through a lot of story, so they might condense his voyage down to a few episodes at the most.
ALSO the Stannis and Shireen scene was awwwwwwwww. Stannis is a good dog. A good grumpy frowny dog, but a good dog.