As to character death, I'm the billionth person to point this out, but I honestly feel like the Quicksilver death is in response to Days of Future Past announcing they would use Quicksilver (not a response to the film itself as both films were obviously at different stages of production at the same time).
Also I wasn't too bothered by the Hank Pym/Tony Stark switch. I mean both are egomaniacal jerks who are still super smart and do care (although Hank was always one to go the extra mile, but Tony still has his share of mishaps) so to have a scientist bad boy create the villain worked for me. I also loved the Ultron/Vision/Tony dynamic. Spader's Ultron is sort of another side of the coin to Tony with Jarvis/Vision then becoming the almost antithesis for that.
Finally, I agree what 1SO said about Cap 3. It almost feels like it's going to be a more significant film in terms of impactful events. I mean the fact that the Russo Bros and the writers are going on to do Avengers 3/4 and look at the cast...
Chris Evans, Robert Downey Jr., Scarlett Johansson, Sebastian Stan, Anthony Mackie, Paul Bettany, Jeremy Renner, Don Cheadle, Elizabeth Olsen, Paul Rudd, Emily VanCamp, Frank Grillo, William Hurt, Chadwick Boseman, Daniel Bruhl and Martin Freeman.
Sounds more like an Avengers movie the more I look at it.