I wish I could get into the theories at this point, but they just aren't pulling me in like they used to. With only two episodes left, we are unlikely to get a reveal of some complex, unexpected narrative thread.
Jon is gonna kill Dany, or Dany is gonna kill Jon. That's basically what this boils down to.
We'll probably get Cleganebowl, because fan service, and Arya will probably live, again because fan service.
Varys is almost definitely gonna die, because we found out that Melisandre actually REALLY knew her shit, and she said he was gonna die upon his return to Westeros. There's no way that the show leaves it as an unresolved thread for us to just assume that it happens down the line.
Jaime is almost definitely gonna die. It's the perfect close to his redemption arc. Either he completes the redemption and dies in the process of trying to kill Cersei, or he refuses his redemption and dies trying to save her.
Cersei is gonna die, because the final conflict is set up to be "Jon vs Dany," and you can't have that as a worthy final question unless Cersei is gone.
Everyone else is gonna live, or else it won't really matter if they die.
Unrelated kind of, but I really thought the last "surprise" was going to be Yara showing up with Daario and the Second Sons to help offset the presence of the Golden Company.
It could still happen, I guess, but it's basically a moot plot point. Yara's service would have been to counter Euron's fleet, but that's unnecessary now. They're at the gates of King's Landing; the sea is a non-factor.