Also, the majority of the 'kill x amount of mobs' quests are integrated as bonus missions. You'll be given a quest to go do something, and when you kill a mob while getting to that, a popup will appears saying 'Kill X amount of these mobs'. Completely optional, but theyve obviously done it so that if you're going to have to kill a load of mobs to get to the main goal anyway, might aswell do this for some bonus xp too. It completes instantly when you've completed it, so no running back to hand in. It's well done imo.