Hey, this looks great! I like the idea of all the separate worlds floating in the Ether. By the way, have you heard of this homebrew?:

http://www.giantitp.com/forums/showthread.php?t=252794

I think it would work well with the technology system in place here. They may also be more useful than Wizards, given the changed nature of magic. Just a thought. Also, keep it up! This really looks like you've thought it out nicely.