Re: Should the archenemy be first?
If I was my younger self I would have said the archenemy should always be first since I was so used to seeing it in movies like Spider-Man, Daredevil, Fantastic Four, X-Men, and Batman.
These days, I'd say wait a movie or two before introducing the archenemy. Build him/her up.
Superman/Batman, Avengers: Age of Ultron, Star Wars: Episode 7, Ant-Man, Daredevil and Fantastic Four ... The world isn't prepared for 2015.