This is largely up to your judgement - one topic is probably not enough, but you need to discuss each item you cover in a reasonable amount of detail, so you won't be able to discuss every item in a ten page essay. The essay should be 10 typed doublespaced pages. Some variation around that value is acceptable - much less than nine or greater than eleven will either not cover the topics in enough depth, or will irritate the person marking your essay. You can agree or disagree with each subject, but you need to be able to defend your opinion with scientific arguments. Material should be referenced as it is used in the text, and quoted if appropriate.
Primary sources are preferred.
URLs are unreliable and transient, but are good sources of ideas, if checked and confirmed, and should be credited along with a primary source. Comments about the story can be used briefly as introduction or for smooth transitions between sections, but a plot summary or book report should not be included. More than half a page of plot summary will be discounted as padding. The textbook and notes are a good starting place, but you will need to go to other sources to write the essay in enough depth. Web based material is acceptable, with a few caveats.