It would be fine to wear over Chanel's blanc universel, btw I love that stuff although it's a bit expensive as well. I put on a yellow stick under my eyes to help camoflauge the green & then I dab Clinique concealer over that. You can also put primer on before BM, I use either MAC's strobe cream or Loreal's skin Illuminating cream. It looks really good underneath the Bare Minerals & gives you that glowy look. & yes you can use normal powder blush over the BM, I usually finish it off with MAC's blushbaby! So I'm certain it'll work. & that MAC brush I mentioned early is expensive, which is something I had a problem with at first but imagine how many times you'll end up using it as long as you keep it clean so it's a good investment. Natural bristles work so much better in makeup application & I've never tried a better buffer brush than the MAC one, & trust me I've tried quite a few ranging from all different prices.