What is the best way to get my first chaotic?

You are actually a much higher level character than me in both combat and dungeoneering, but I figure I'd try to help anyway. Reseting your progress could probably help you earn lots of xp. You basically strip all your progress away and go back to floor one. When you do this, you get your prestige back for all the dungeons that you've completed. So you could start at dungeon 1 and since the dungeons are very easy for you, go through a number of dungeons all in a row and get the prestige xp you get from completing as many dungeons as possible. Other than that, I use all my dungeoneering points to buy xp lamps from the rewards shop and get more duneoneering xp.