Extra protein could also be from cooked eggs, soy products, chicken, etc. The rest of the items the pet shop recommended are totally useless for rats. Rats do not have a need for added salt in their diet. The light is also not a good idea. Why they recommend a cuttlebone is also a mystery.
Rats enjoy some shady sunlight but are nocturnal creatures.
I can't imagine why the vitalight would be recommended, especially for something with skin as sensitive as a Hairless rat.