Leading straight in from the last point, the amount of fringe characters means that the main men and leading ladies don't get enough time to really shine. We're watching this show for Rick, Carol, Daryl, Maggie, Glenn, Morgan and to an extent, even Carl, but their roles are diluted to make room for filler. The focus needs to be squarely on the main cast, with their characters providing a huge amount of talking points, intense drama and fantastic performances. The first change should be to include Rick Grimes in every episode. That sounds horribly basic, but it's true. This is his story, let's keep it that way.