Re: Peggy's status
I think with the love they set up between Steve and Peggy, and how he still loves her and thinks about her in the Avengers, and how SHIELD could easily take him to London, I would like to see him visit Peggy. Maybe see that she moved on, had kids, her kids had kids. Something to help Steve and the audience know its okay to move on.
However if Steve finds out that she has died while he was frozen and visits her grave to say goodbye then that also would help him and the audience to move on.