Hey, been awhile since I checked on this. Explosions, and whatnot.
Looking back at these posts, I do really like the ideas, and it seems that you have addressed most, if not all of the problems that I saw. 

I agree with Cyclone- Air, Earth, Fire, and Water is just a bit too cliche. I could throw out some ideas to make new, but original cities, but I don't think this website supports that many characters. 

Now that I have free time, I will be more active, and actually... Here and stuff.