Sure you can! He went into hiding twice! Easy peasy. :DYes, but you can't have USM take place between both Avengers seasons if Nick Fury has also gone rogue in between them.
One year? Yup, works fine. :DSure, the Odin Sleep + the Comatose lasted years, Maria Hill wanting the Avengers to register took years, the Heroes starting as heroes didn't take a few months with their Asgard adventures but entire years, yes everyone was a slow poke, clearly. Watch the actual show.