The compare and contrast essay requires you to look at the similarities among the 3 characters but also to contrast the differences among the 3 characters. Considering that you need 5 quotes per paragraph, these paragraphs will be quite long. I would double check that requirement. I would first make a list of the three characters and a column of similarities and differences among the three. You can then structure your essay with the similarities and differences among the characters using the points you have listed. I think if you structure your essay around the characters as you plan, you will have a lot of repetition. Maybe look at two similarities and one difference especially the idea of revenge. Try writing one paragraph your way, one my way and see which one works the best for you.
This is perhaps one of Shakespeare's more interesting plays, if you will. In comparison to Macbeth it isn't quite the walk in the park.
I think conceptually it enables the reader to see that characters can influence characters to such a degree that the original traits are masked and changed. Tragedy in this play is definitely a main component - and a great emphasis that perhaps the villain doesn't always find their true defeat. In a way, wasn't the "villain" successful? He lied to everyone and pretty much killed whomever got in his way.