Also, TrPrado, GoT doesn't kill people off for no reason. Ned's death was a catalyst for future events. The Red Wedding was a catalyst for future events. Oberyn's death was a catalyst, etc etc. But the second we got past the book material, they stopped being that. They were just....deaths. Stannis' death meant nothing. Barriston's death meant nothing. Ditto for Littlefinger, Rickon, sand sneks etc. The only ones they've actually gotten right are the sept in Season 6 and probably Thoros this year. Both of those deaths have wider implications. The problem isn't so much people not dying, but stupid writing putting them in situations where realistically they should die.
Also, no ravens don't turn white in the winter. A white Raven is sent from Oldtown to each castle to tell the lords that winter is here. Yes, Jon's claim to the throne supercedes Dany's by the laws of Westeros. Any man comes before a woman. They fought a civil war to establish that precedent (Dance of Dragons). And just as it is in the book, no one really gives much a shit about what Robin Arryn thinks. The lords there were ready to depose him no matter what, which is why Littlefinger had to befriend the cadet branch of House Royce to beef up his support.