I never got mine to work properly. I just gave up. I tried everything. I made my snowflakes by hand with white chocolate. Wish I could offer more suggestions myself
I add it to mine all the time. Creme Royal flavoring is awesome in it. You can add just about any flavoring you'd like. Just remember to cut back on the water used by the same amount of flavoing you add to the MMF.
I'm not sure where you're located, but I would start by pricing some cakes at local bakeries. I've asked and heard other people state what they paid for cakes at bakeries in my area and knew I was within my price range.
I've also done mine both ways. If you are scared to mess up your KA mixer, begin with the mixer, let it incorporate some of the confectioners sugar, then sift a nice pile of CS onto your countertop, dump the somewhat soft, sticky lump...
Sounds like you may have gotten a bad batch of the mix.... Pillsbury is all I've ever used. I always doctor mine and have excellent results ... I can't imagine why it would have done that ... strange