I wonder if putting nursing pads in your bra would help? You'd get some cushion/padding, and they're designed to absorb moisture. If you get a set of the reusable, washable cotton ones they breathe pretty well (the disposable ones with the adhesive do not) and it might also cut down on chaffing because the pad kind of conforms to your breast and doesn't always move every time your bra shifts.
I don't have any experience with nipple piercings (the very thought makes me cringe!) but I have LOTS of experience with having to keep that area as dry and happy as possible to avoid cracked nipples and infections while nursing my two kids!
Pan Female, Hinge in a V between my mono (straight) husband, Monochrome and my poly (pan) partner, ThatGuyInBlack