6 weeks is too young for a puppy to be taken from his mother. Not necessarily for phyiscal reasons but for mental and behavioral reasons.
Get rid of the human baby rice cereal. The dog is a carnivore and has no need for plant material.
Sorry, I don't feed my dogs or cats kibble so I can't help you there. I don't know anything about kibble sizes.
Boiled dark meat chicken is good. Raw dark meat chicken would be even better.