1. I think the narrator describes his life at home and at school as “inessential” in comparison to the life from the exciting stories of Eduardo because the teenager thinks nothing interesting happens in his life. The narrator probably thinks that, when he is at home or at school, he doesn’t really live as all he does there is obeying others’ rules and following others’ expectations. I also suppose the boy thinks that the world of his home and school is too narrow and limited compared to the big world of Eduardo’s stories. The scale in these anecdotes is completely different from what the narrator is used to.
2. Miguel is angry because he realizes all the injustice and terrible state of his life circumstances, but he can do nothing about them, so he feels trapped and helpless. He probably wants to channel his bitterness, grief, and rage towards those who were unjust to him and caused the current situation, but the only available recipient is the narrator, a privileged one and a temporary embodiment of the Mexican’s oppressors.
3. The hotel room becomes an embodiment of Miguel and Eduardo’s tragic situation: them being trapped by the external circumstances and having no power to change anything and no control over this situation. It is even more evident in case of the narrator who literally gets trapped in the room suspecting he will be killed, but can do nothing about it except keeping silent and smiling. The later contemplation of the narrator makes it obvious that the room is a symbol of people having no control over their lives and feeling powerless in the face of unexpected tragic circumstances.
4. In Moby Dick by Herman Melville, the white whale is a symbol of powerful and incomprehensible force of nature that a man tries to conquer, but fails. In a way, Moby Dick is also a symbol of fate associated with unavoidable death.