Really glad you came here to ask because I did in the beta forum but no on answered. ^^; That's alright though. You should leave those quests undone and just follow the main storyline + any level appropriate quests you find along the way. You want to leave them because those quests are extremely good boosts for leveling other classes. It's difficult just starting out with a new class, the easy 5 levels from those bundle of running around quests make things much easier.