Spoiler (highlight to view):
That fight between Jon and Qhorin is supposed to be a shitton more convincing and happen in a less canned fashion. The show was all "hey, you two, fight to the death," whereas the book has Qhorin very convincingly attempt to murder Jon, who wins mostly because his giant fucking wolf helps him out, and the Gingers buy it because it looks like a real defection.
As for that giant undead army, it's not supposed to happen in quite that fashion. Sam accidentally kills one of the white blue-eyed dudes by flailing wildly and tripping onto him with an obsidian knife, but only after said white bastard has killed like three people. The actual zombie army is setting up to raid the shit out of the Watchmen that were fortifying that circular fort we saw halfway into the season, but since those scenes are so disjointed, no one has any clue that's what's going on. Like, turbo-double-spoilers: those white sons of bitches are the real antagonist, but everyone's too caught up in their own shit to notice or care. All the humans fighting each other is icing on the cake, really.
And every bit of the season that happens in Qarth is infuriating. I like Emilia Clarke's tits as much as anyone, but none of her season 2 scenes ever happen.
If destruction exists, we must destroy everything.
Shuruppak Yuratuhl Slaad Shrpk Breizh