Well, I bought Episode 3, but I'm stuck too, on a certain glitched quest. A way to level up without doing main quests (or side quests, for that matter) would be Aether, if you have gotten to that part yet. If you collect gears, springs and other random glowing things lying on the ground, it helps fill your Aether. Once you have Aether (full or not full), you put it into the Engines (I do it at the Town Square) and it gives you Experience Points, which help you go to the next level!
Phew! That was a lot... *pulls a Vytanni *