Well someone had this probelm before with a new pad and they didn't wash it before use. Pad manufacturers shave the foam to get it into the shape and the result is pieces of foam that can get stuck inside the pad which could look like product dust.
PB products
can dust but once you figure out the process that works for you, they won't. I don't prime my pads with anything except the product with the SSRs. Also, I use polishing pads, not sure if that makes a difference or not. It's hard to tell you an exact amount of product to use, but play around and be observant to see what works the best/easiest. I rarely get dusting when using the SSR line, and when I do it is because of a water drip from the mirror or something - water + SSRs do not mix

.
Dusting is a pain in the you know what. Every product, every car, every pad, every change in temperature & humidity can effect how a product works and you may need to take this into consideration when detailing. So you may have to play around a little to find the right techniques but I assure you a little more time will yeild the results you are looking for.