Well we have an established pattern of extreme stress and abuse that prompts DID to develop.

Schizophrenia can emerge from traumatic experiences or things like drug use. However, it also occurs in people that live relatively calm lives.

I would be curious to know why the mind would use Schizophrenia as a healing mechanism in some that are only lightly emotional disturbed yet can almost entirely neglect those that are severely traumatized.

I could see a healing component of Schizophrenia but I would have to place it into the context of mental illness. Those with Schizophrenia tend to experience an improvement in the disease as time goes on. However the improvement is not fast enough so that the person would have any real net benefit, without treatment.