I actually kind of miss the earlier alphas where we had more quality levels. Even with the linear loot and the slowdown it causes it's still so quick to go up to tier 3 or 4 of things since there's so few loot quality tiers.
I agree completely. If I just wanted to kill zombies I'd definitely pick something else to play. The building has always been what set the game apart from others for me.
Challenge quests giving xp instead of skill points. I understand that if they give skill points is would defeat the purpose of the level cap and wanting people to specialise, but it does make them useless once you reach the cap.