By acting in a way that discourages them from hurting you, and encouraging them to help you, you are playing your part in maximizing total happiness.
Not necessarily. If I horribly torture Jim because Jim stepped on my toes, then I am not maximizing total happiness; the unhappiness given to Jim by the torture outwieghs the unhappiness in me that is prevented by having no-one step on my toes.
Here's the new thread for posting quotes, with the usual rules: