By refering the one as a WW and the otehr as a campbell, I presume your judging on their colouration? Pet shops usually sell campbell x ww's (hybrids) which vary in colour and body shape.
1. Hybrid dwarf hamsters are more likely to be born with health issues or deformities as they should not be bred. Its not certain the mother will have birthing problems, but its best to observe her to ensure she doesn't appear in pain or distressed. As you say she appears pregnant its likely she'll give birth within the next few days. The female often kicks out the male before giving birth also.
2.yes the male should be removed immediately. Introducing male babies to him is an option as long as he is willing to accept them.
3.Extra protein is brill, make sure to remove her wheel and anythign that could be a danger once pups arrive.
Be sure to keep handling to a minimum once babies are born, she needs to keep her attention focused on them.
Best of luck