1.I was personally thinking around 1830 ish for the tech.Nice, unlike other world-building projects, I'll try to circumvent what made them stagnate and let you work on what you wish to and then we assign them together a part in the history of the cycle of ages or in the last age depending on how the nation is. Then we can work backwards and maybe construct more of the background. You can try with non-humans as well. No problem.
It seems like nice setting, although I would diminish a little the power of the US-parallel so as to have a multi-polar world.
Which year, technology-wise, are you thinking of?
Also, I think we can both come up with something better for a name.
2. Also, I think the Cataclysm should have divided the world like this:
a. There is the Known World, where science dominates and magic has died out due to the Cataclysm. This is where the big empires that I mentioned earlier are.
b. there is the Far Lands, where magical beings roam and wizards dominate. The known world has colonies here. Some even separated and founded their own nations, including the U.S equivalent.
c. If you travel even further from the Known World, physics as we know it starts to break down. This point is called the Horizon. It is completely uninhabitable, and some even say that beyond the Horizon lies Hell itself.