Tim, welcome to the site....my wife is from Iowa, and I have never met an unkind person from that state. Must be something about the way of life over there.
To your question about becoming a certified casting instructor, I guess that there are a few questions you should ask yourself.
Why do want to become certified?
How practical will your certification be (that is, how much and in what way will you be able to apply it)?
What's your timeline for completing this?
And one question I have for you....are you aware of just how difficult this can be to accomplish? Depending on who's certifying you, it can take a great deal of experience, practice, commitment, and time to reach a certifiable level.
I'm not trying to discourage you, only trying to understand what your driving force is for setting out to do this.
I've been told that I'm certifiable, but I don't think it has anything to do with casting.