You can discuss only one example but provide a thorough and detailed, insightful analysis of it and prove your point. On the other hand, you may offer 3 or 4 different examples but provide no deep understanding or observation of it. Worry less about quantity and more about quality. Conclusions should summarize your essay's main points. Just like the titles of a novel or film help to interest consumers, the title of an essay also captures your reader's attention.
Every quotation needs analysis.
While you can assume that the reader has read what you have read, you cannot assume the reader has understood the material in the same way. You do so through the explication of your evidence. Simply put, do not use a quotation to replace your own words or ideas. Avoid profanity in a formal essay. Many people praise author Richard Rodriguez's novels, but I think he's a fucking sellout.