Yup! That's a stave alrightey!
Don't get yourself all het up over twist yet. Let's get you to a roughed out stage first.
As for bow design, one of the simplest and most effective is a "bend thru the handle D bow". There are no fade-outs or stiff handles, no recurving or decurving, just reducing thickness a little at a time here and there until it bends in an even arc.