You don't have to raise the rooster and the puppy together for them to get along, all my roosters get along fine with my dogs and they did not meet until they were adults. A rooster can cause harm to people of all ages if it is aggressive. Raising a rooster with the kids won't stop him from turning into an aggressive rooster. All of this just depends on the bird, weather you raise it with or without something won't really have any effects on the bird's temperament.