Here's the answer to NEARLY all Mooshu Questions: Do all the quests!
Seriously. A huge percentage of the posts we see here are because the players tried to rush through the game, skipping anything that didn't directly advance them to the next zone. And then they come here wondering why they can't get the next quest, or can't get into some room.
Hunt through every zone. If you see a punctuation mark over somebody's head, go see what they want. You'll save yourself a world of trouble.