hypothetical questions

[thesmeagle]

I'm writing for a sci-fi comic, and we'd prefer to be reasonably scientific, so I and a friend of mine decided to run some stuff by you folks who know what you're talking about.

 

A few of our aliens are (roughly) humanoid insectoids. As a rule, insectoids don't get above a certain size in an Earthlike atmosphere because they would need extremely strong winds and/or very high concentrations of oxygen to breathe. Any suggestions as to how a very large insectoid might evolve to breathe Earthlike air (with reasonable accommodations like an artificial respirator, that isn't too unsightly?)

 

One hypothetical creature in our universe is a VERY large moth that lives on a very turbulent world; assuming it isn't storming already, the moth could theoretically stir up a small storm with its uniquely shaped wings. Reasonable or not?

 

One of our planets was a civilized world that was generally a very sandy desert; due to an orbital bombardment with extremely powerful thermal weapons, much of the planet was turned to glass. Assuming that a person on the planet survived the initial impact, would any of the planet still be considered habitable, with or without life support equipment?

 

Finally, we're going with the (conspiracy) theory that the most recent Ice Age was in fact caused by a botched terraforming attempt. Is this reasonable?