The Purina Puppy Chow should be fine. That was what the dog guide school was using when we started raising puppies in 1991. The main reason for switching to the Pro Plan was not for the dog's health, but for the small, firmer stools that are easier to clean up. Still, you should switch to the adult version soon. I would cut out the the extras too. The Purina is formulated to be exactly what the dog needs. As for how much, I do have a good website for that,
http://www.purina.com/dogs/nutrition.asp?article=292.
I strongly advise obedience training, but don't have a good website for that. The dogs see all the
people and dogs in the household as a pack with each having their own rank in
the pack and a top dog. Life is much easier if the 2 legged pack members
outrank the 4 legged ones. You can learn to play the role of top dog by
reading some books or going to a good obedience class. A good obedience class
or book is about you being top dog, not about rewarding standard commands with
a treat. Start at
http://www.dogsbestfriend.com/. Unfortunately there isn't too much there except hype about their books. In America, the bookstores and libraries are full of books on dog training, and all I usually try to do is to help choose a good one. There is a lot of nonsense on the net. There are no standards to keep kooks from posting whatever they feel like. Maybe I will do some looking around and get back with you.