1. Mr. Luggs: suck up some of his ghostly food after you light the candles with your fire elemental. Some normal ghosts will appear. Suck those up. After you do that, suck up the rest of his food. He will shoot fireballs at you. Dodge them until he gets tired of belching fireballs at you...
If you need any help whatsoever, I beat the whole game twice in a week and a half.