This is very creative and beautifully realized. Assuming erosion works on this world, it is heading for a future of being an island chain. What will happen to Nomest culture then? I also wonder what effects this geography would have on realistic climate. Probably best that this is a fantasy world and you can avoid having to dive deep into that kind of issue.

You have an "it's" for "its" error in the first paragraph.

I especially liked the history of the concept of the center of world. It would also be interesting to consider the huge changes that would have appeared when someone first figured out that you could take a ship over a fairly short distance to travel to a once very-distant land and trade, war, diplomacy, and every other form of relationship between peoples was shaken up.