Am I feeding my puppy correctly?

Question
Hi, I have a now 6-month old purebred doberman.  He's now 71 pounds, has
a shiny, glossy coat, full of energy, gets a enormous amount of exercise every
day.  He's never been a good eater.  I'm now feeding twice per day, he's on
the Evo Innova large puppy breed dry food.  He doesn't eat it (the breeder had
him on it), so I tried samples of the other large bred foods -- he didn't like
any of them.  I'm now adding organic chicken broth, a bit of raw ground
turkey, a glucosomine supplement, and pet tabs -- and he's eating!  I get
many compliments on how gorgeous he is, but I'm wondering if I'm doing the
right thing by adding more stuff.  The vet says his weight is perfect (he's very
tall) and he wished more puppies came in looking as good as this one.  Do
you think I'm okay with adding so much, and should I add anything else?  
Also, he's in training and I'm using dehydrated chicken as training treats.  His
stools are usually pretty squishy -- too much chicken?  Any advice is
appreciated, I just want to do the best I can for my buddy.  Thanks, Karen

Answer
I really wouldn't give pet tabs at all. With what you're feeding the only supplements your dog really should need is vitamin E, vitamin C and fish oil. Too much protein and fat could cause Pano or HOD.
As long as he continues eating., then I wouldn't worry too much about spoiling him or about what you're feeding. If he starts refusing what you're feeding him now you're going to have to get tough.
Right now,. I'd say GOOD JOB. You might want to add some Nzyme drops to his food every day, that would likely end the squishies :)
Cindi