I thought I would be the same with my second time playing through. But even though there are a lot of the same quests, the different classes have different reactions and motivations and there's a whole other layer when you start doing DS and LS as well. Going into the game again I really thought I would be agreeing with you but I'm very happy to say I'm enjoying all the cut Scenes second time through

I do remember reading somewhere BW saying that the main voice actors have it in their contract that they will have to come back in to record more dialogue for future expansions.

I think this behaviour is an acceptable part of the game and if that's the way people want to play it reflect back on them and their play style. when a player does this to me I form the opinion that he will just play as selfishly in a group situation and use the world chat function to warn it other players. hopefully it will be harder for them to group. If nothing else it really ticks them off that you call their behavior out in front of everyone and have gotten into huge arguments with them before. Loot ganking is part of them game, but so is naming and shaming