The breeders that are on this forum are not "professional breeders" either. Most are what people refer to as hobby breeders. Many don't have kennels, breed occasionally, and show, course, race, do agility, etc with our dogs as part of our relationship with our dogs.
There are many people who own a couple of dogs and think they will be "helping" either people or the breed if they breed them since they are just such fantastic companions that they must be exemplary specimens of the breed. Unfortunately, that is not always the case. Everyone on this forum loves their basenjis and in their eyes their dogs are the epitome of "basenji" but from a breeding standpoint that may not be the case. The hardest thing as a breeder is to look at your dog with a critical eye and ask "What does this dog have to offer the breed?"
Were both of your puppy's parents DNA tested for Fanconi? Did you verify the results on the OFA website, http://www.offa.org, to be sure that at least one tested Clear? Did you make sure the parents also had a hip rating and a current CERF exam? Did the breeder have CERF exams performed on the puppies before sending them home? This is especially important if you bought your puppy as a show/breeding prospect because PPM is at its worst when they are puppies so it would be important information when selecting for health.
As for "grading", typically a breeder will grade their litter at 8 weeks old, which is when the pups look most like what they will look like as adults before they start going through funky growing stages. At this point, the breeder will look at each puppy's conformation and grade them against the standard and decide which have potential as show/performance prospects and which are best suited to pet homes. Just because a puppy comes from spectacular parents does not mean it will turn out to actually be show potential.
If your breeder was not able to discuss with you the strengths and weaknesses of your puppy based on the standard then I highly recommend you get together with some basenji people and have them go over your puppy. Be prepared to hear both the good and the bad, no dog is perfect, and if you are serious about showing it can be really discouraging to be at the "back of the bus" and not understand what the judges may be seeing that you are not.