Another more directly worrying question, is why or if the p-zombie philosopher postulate that other persons have consciousness.

A wonderful way to dehumanize.

therefore letting go of all forms of caring for others and all morality ?

The meat bag you ride will let go of caring, or not.

Under the theory, the observer chooses nothing in the physical world. The meatbag produces experiences of caring for you, or not, according to his meatbag reasons for action in the world.