I can imagine the problems you face if your H does not adequately manage his blood sugar. My wife’s stepfather is an insulin dependent diabetic who does not manage his blood sugar properly and an alcoholic, he came onto my wife sexually last summer so something is really screwing his head up.
I agree respect is very important. It is a cornerstone of a good relationship.
The only thing I can suggest with your son is try to be a good role model and make sure he understands right and wrong when it comes to relating people. As he grows up his eyes will open.