Most people only add about 10% angora to a project when they blend it. Seems to give enough softness without too much halo. Not sure exactly since I rarely blend mine.
As far as using Koolaid to dye fiber, I had a friend that used it, and I believe she just played with it. She seemed to do a pack of Koolaid with approx. 4oz of wool, and then used about a cup of vinegar to help set it. I use acid dyes with vinegar or citric acid to set, or natural twig and berry dyes with food grade alum to mordant, so again, not entirely sure on this, just trying to tell you what I know of it!