8. Having Every Key Character Emerge Unscathed
In seven Marvel Cinematic Universe movies to date, we have yet to really see the death of a single significant beloved or "good" character - Agent Phil Coulson came close in The Avengers, of course, but that's been undone. Thor: The Dark World is the first MCU movie in which the threat posed is universal - Malekith's plot to plunge the universe in to darkness could kill life on a grand scale and his forces could potentially overrun planets all over the galaxy. With that in mind, if the likes of Jane Foster or Darcy Lewis - or even certain characters with more power than those two - come away from the events of this movie unscathed, something is seriously wrong. The viewing audience are going to start to believe that there is no threat to any of the key characters in any of the movies in this continuity and that takes away the "edge of your seat" feeling that adds so much to any given movie experience. Marvel need to pluck up the balls to kill someone off so that we know the heroic and beloved characters in any given movie are at risk - otherwise having villains in any of the movies will begin to feel pointless.