Yes you can feed raw bones (I only feed raw diet and have raised puppies on this diet.) Chicken backs and necks are fine for a pup that size (I do aussie rescue and feed these to puppies frequently)
It is perfectly OK to feed raw and use prepared treats. Although some people speak against it, I also think it is perfectly OK to feed raw one meal and kibble or canned for another. I have never seen a problem from that, although I advise against feeding anything with whole bone at the same time as kibble, some people think the kibble soaks up digestive juices that should be dissolving the bone. I train for flyball and train rescue dogs for adoption and I use prepared treats, it would just be too gross to use raw meat!!
As mentioned above you do not want to overdo calcium, because puppies cannot eliminate excess calcium as efficiently ad adult dogs. When i feed puppies raw, I always make sure that no more than half of the total diet (just by volume) is raw MEATY bones (even even a little less if you are not sure). This should get you into the 10 to 15% total bone content range for the whole diet, because meaty bones are bones and meat. There are two ways to estimate bone content that people speak of in raw diets, total bone (i.e., how much actual bone they get) and raw meaty bones, which since they have bone and meat are only a portion of actual bone.
Feed the balance of the diet as raw meat, with a little organ meat or eggs.
If puppies poops look too hard, you are feeding too much bone. If puppies poops are too loose, you are either feeding too much food overall, or to much fat or organ meat.
These are items you can feed a pup that size that you may find around at your grocery store:
Any chicken part cut to size.
pork neck bones (sometimes I can find these cut to size, I guess people make soup)
any ground or whole meat portions.
eggs (start with one raw, these can soften stools)
liver, kidney (start with a small piece, and never as a large portion, because they can really soften stool until a dog is used to them)
