The personality of a dog is flexible and indeterminate. Dogs can be exuberant or shy; friendly or hostile; fearful or bold; aggressive or passive or some combination of the above. These differences in personality may to some extent be determined by breed, or individual genetics, but for the most part it is based on how and to what extent each particular dog has been socialized.
All dogs need to be exercised everyday in some form or fashion. The most common method is through the walk around the neighborhood, but is a short walk around the block enough exercise for your particular dog?
Is there such a thing as the perfect puppy? In all likelihood there is not. There is always something one might change in any dog (or person really), but the goal should be to always strive towards raising a puppy to be its most perfect self. This is hard work, to be sure, but it is not only possible, it is necessary.