The question is very self-explanatory.

I want to set my stormcasts somewhere outside of Azyr, but I'm not sure what's the look of the other Realms. I mean, does Aqshy need to be a volcano-ridden land of magma? How do they people there grow any food at all? I know Warhammer doesn't care about actual economics or realism, for that matter, but I need a semblance of reality in order to believe this world.

I guess the people of Aqshy could grow mushrooms and roots underground thanks to the heat of the magical geosphere...

Another thing: are the Realms flat? Or are they composed of moon-like planets floating around? I like the idea of floating worlds orbiting bigger worlds, it certainly makes for interesting skies and for cool airships.

Anyway, just trying to get a glimpse of what GW are not showing in the army books.