Oh, keep the Vienna! It gives a nice character, without adding sweetness. Sometimes I'll use Munich malt for the same reason.
I like the hopping. I love simcoe and amarillo together (drinking it right now, as a matter of fact!). You've got amarillo 10 minutes twice, so I'm not sure what that means, but I'd try to have 1 ounce at 15 minutes (or 10), 1 ounce at 5 minutes, and 1 ounce at 0 minutes of the amarillo/simcoe combo, and use .5 ounce of simcoe and 1 oz amarillo for dryhopping.