Since Rarity's primary spell is "Detect Gem Deposits", does that make her a Geomancer or a Diviner (specialist in Divination)?
That would be Divination, but I've always figured that even if that spell was what kicked her off, she probably specialized in Illusion later on. Seems more her style.
which implies that there is no water evaporation in Equestria.
Not necessarily, just not enough directly under pegasus control to handle year-round weather and irrigation for all of the large cities. Remember, they've still got wild weather in the less civilized parts (Everfree comes to mind), and they have to actively stop it from blowing in. And the usual weather patterns are dictated by evaporation from staggeringly vast swaths of ocean, and there's no way Cloudsdale would be able to handle that much open space.
My theory on "what if no more weather control" is just that they'd adapt to natural weather patterns. The unicorns would piss and moan but suck it up after a while. Before the Princesses came around, the unicorns as a whole were handling the sun and moon, and I can't imagine Celestia hasn't thought of a safeguard in case nobody was able to manage them at all. Really, I'd be more concerned about the extent of the fallout of whatever
made them disappear.
edited 28th Mar '12 12:31:04 PM by Pykrete