You know Dragon's Mouth Cave? There are two tiny cracks in the walls. I think they should make this into a house. There could be new boats that you can pause to hop off at any time, at any place of this castle. There should be some built in features, like a lava fountain or something. I got this idea by seeing if I could go into dragon's Mouth after I did the quest. I could, and I love the appearance. It was small as a dorm, but I saw the gaps. There should be hidden passages, different paths, and more inside of the house. Just imagine.