First, on the "wash coat" question...a water soluble dye stain isn't going to work very well if you seal the wood first.

Personally, I always put a barrier coat between water soluble color and my water borne top coats just to be sure there's no issue. Some folks don't do it, however. My suggestion is to make up a couple of test pieces to finish in various ways to see what works best for you. A sprayed light coat of the Target finish will "likely" dry quickly enough not to mess with the color, but testing is the only way to be sure...