But George RR Martin is a sadist, and he said he likes killing characters people like. Besides i said caring too much about your characters. I'm thinking along the lines of Gaias from Battlestar Galactica who should have died in season 2, but got carried to the end of the show (in season 4) so on, so on.
And on the note of television, a Song of Ice and Fire was a direct retaliation to the executive meddling and production constraints GRRM had experienced in his 30-year career as a tv-writer. When he sat down to write A Game of Thrones he set out to write sets as expensive as he wanted, as extensive as he wanted, and he could kill whoever he wanted. You'll find he's not nearly so "sadistic" in his other fiction, and certainly not in his television writing (excluding of course the episode he wrote for Game of Thrones on HBO).