The Hound may not be dead. There was no fight between The Hound and Brienne, but Brienne does see somebody during her search for Sansa that many readers are pretty sure is The Hound, AFTER his apparent death, serving as a simple monk.
The Mountain is another maybe. The poison on the spear was a horrible one and The Mountain died in agony. However, Cersei's new pet non-Maester took the body for his studies, and later a new member of the King's Guard shows up - a HUGE man who never removes his helmet. Note that this is AFTER the apparent beheading of The Mountain.
I was a little saddened at the changes in Tyrion's escape and Tywin's death. Jamie, while freeing Tyrion, admitted the young girl Tyrion had married at age 16 was NOT a whore - that was a story Tywin demanded be told to force Tyrion to divorce the girl. That girl loved Tyrion, and when Tyrion demanded to know where she was sent, Tywin said "Wherever whores go" and got a crossbow bolt through the groin for his troubles. Tyrion hates Jamie now because Jamie was in on the secret and had lied to Tyrion all these years. As for Shae, in the book she was NOT in love in Tyrion but was a gold-digger, and her betrayal of Tyrion and showing up in Tywin's bed enraged Tyrion into strangling her.
It’s going to be a long time between the next season. Now I will have to read for myself what you have explained.
Martin really is a genius storyteller.