i have about a dozen animals w/ various stages of ringers.
yes, it can but it depends. breeders may charge more for quality or it's visual appeal or genetic potential and buyers may deem it worthy.
sure. for example, i have a Dave Green Champagne-combo from his extreme ringer-line. it basically looks like a mid-white Pied. DG-line Champagnes have consistently thrown mid to high white ringers. Dynasty Reptiles (DR) also has a line of their own ringers.
if it comes from a Pied parent (or has had Pied in it's lineage), it can be an indicator for being het Pied. otherwise it's mostly just another (random) pattern like a paradox.
very good questions. hope my experience helps.