Quote: I misread. When you said "toe nails are white," I read "toes are white." That could be pigment holes. White feathers aren't.
Breeder quality is kind of hard to get a handle on. Some birds produce very good offspring, but for some reason don;t show as well themselves. And some birds that show really well don;t produce offspring that are as good as they are. It is partly how they are paired in your breeding pens, taking into account their specific geneset and a very unscientific dose of good luck. Breeder quality birds may fare well in smaller shows with less stiff competition, or they may have disqualifications that prevent them from doing well at a show (for example incorrect number of toes).
Show quality means at the very least that the bird is reasonably close to the standard and has no disqualifications. But it can mean a near perfect bird. And everything in between.