Congratulations for trying out raw feeding with your dog.
Be sure and read up on the specific "mix" between raw-meaty-bones (rmb), muscle meat (mm) and organ meat (om). The first thing that concerned me was the comment about giving your dog just livers (om). We give only about 10% of organ meat in each meal. Check the amounts and percentages appropriate for your dog and give him some rmb, mm and om combination. Try to rotate various protein sources (chicken, beef, duck,...).
Raw bones should be fine in terms of not splintering. Chicken backs are a usual staple for our dog. How much you have to cut up depends on your dog. Our dog for example, eats the whole chicken back by chewing it up for a few seconds to "prepare" it for swallowing. I can hear all the bones breaking and "softening".
There are a lot of very experienced raw feeders here to help you. Keep reading too.