Iron will not be easy at all to get in the beginning. It's going to require multiple tools, multiple machines. I'm not really against that, but if we do that, people will have unsafe homes for a little while in the beginning.
That's not necessarily bad, since it gives an added danger to make sure you pick your starting zone wisely, to hide from roving bandits.
I like that. But what if the top, floating part had different kinds of images that sort of evolve depending on the number of people in your kingdom? Like it starts off as a hut, for example, then changes to, say a tribal hat when you have 10 people, and a throne when you have 20, and perhaps a crown when you have 50.