The ending to the Civil War storyline shocked everybody who read it: Captain Ameria being shot trough the head. It was perfectly executed, but for the film version, I think Tony Stark should be the one getting shot. Here are the many reasons why:
Robert Downey Jr. has become too important:
Hes funny, hes charming, hes great as Iron Man. But there are just SO many other characters in the Marvel universe! Tony Stark is the avenger to feature the most prominently in both Avengers movies, I think we need to change that dynamic.
It would be a game changer and a true shocker:
It would change the Marvel universe entirely. Stark has ties to everyone. It would be very interesting to see in future Phase 3 installements the impact of his death on the MCU. It would also be totally unexpected, both for wider audiences who are now accostumed to RDJ, and to comic book fans who would be expecting Cap to die instead.
It would mean the beginning of something new:
Phase 2 was mostly made of sequel to previous films, while Phase 3 will introduce us to many new characters. Theyve already started that process with Ant Man, and later with Doctor Stange, Spider Man, and Black Panther! We also know Marvel wants Bucky as the new Captain America. Kicking off Phase 3 with Iron Man being killed would mean the beginning of a new era of heroes. Time for the new guys to shine!
RDJ is simply too expensive:
The guy was paid 50 millions for the Avengers, 40 millions for Avengers: Age of Ultron, and 40 millions for Captain America: Civil War. That makes 130 freaking millions. The other actors in the franchise are paid around 5 millions for each movies. The amount of money saved by not paying RDJ would be monumental, and could help to make better movies.