Can hate be an opiate? Can it calm and soothe and dull the pain of whatever? Is it addictive? How does a body benefit from opiates?

I think it can. Hate is in the inverse of love and has it more in common with it than we'd like to admit. While hate is often portrayed as blood-pressure raising (love can have the same effect, really), hate, especially when shared with others, has the ability to bring people together and soothe them.