I don't mind most of the changes, because they're going to have to tell the story more chronologically than in the books - but their version of Daario Naharis is definitely one that bugs the shit out of me - where's our blue-haired pirate?
Pretty much all eccentricities and idiosyncrasies have been removed from the supporting characters and made into more generic archetypes who could be interchanged with one another. Sometimes, it doesn't really affect it that much, IE despite losing his leech fetish and creepy way of whispering, Roose Bolton has still been made into a merciless and cruel villain, while other times, it's a big fucking deal, IE fuckin' Mance and Tormund being interchangable as generic tough guys.
I love the use of the word cowardice when they just stabbed a pregnant woman in the belly. I know what you mean, but it's still funny.
Well, indeed, it does sound a little funny, but the cowardice is not in willingness to depict terrible actions; it's the willingness to depict characters they want the audience to like committing terrible actions. Black Walder stabbing a pregnant woman?? No problem, just adds to the audience's hatred and anger at the Freys.
But since the beginning, Tyrion has consistently and constantly been whitewashed. When it started in S1 (removing him breaking Marillion's fingers, leaving out that he finished off with Tysha after Tywin's men did), they were minor details in a point in the narrative in which Tyrion IS pretty much "a good guy." But after the acclaim of Tyrion in S1, the character has had all negative qualities and actions (beyond very general, very lite "he drinks a bit too much and likes prostitutes, except he doesn't cause he has his hooker with a heart of gold") removed bit by bit to the extent that when it does come down to what happens at the end of ASoS, they're either going to have to change it or it will seem incredibly out-of-character for the Shining Knight they've made him in S2/3.