At the end of monster Steve says that " my father is no longer sure of who I am Why would Steve's father be unsure ? how sure is steve himself of who he is?."

That is one of the running themes of this story and related to your last question. At the end of the trial Steve is unsure who he is. He wonders if he, “Looks like one of the pictures they use for psychological testing, or some strange beast, a monster.” Steve wonders if his father sees him as his son or merely a friend of King or Bobo or Osvaldo. Steve wonders if, despite his acquittal, is really a monster.