1.) Either a bit of a long fic, or a fic series; early on in the fic/series Steve (in the 21st century) publicly outs himself as gay and says he had a relationship with Bucky. Later on, after they've recovered the Winter Soldier, Bucky hears about this and isn't happy that Steve outed him. (Pretty sure they work it out eventually.)
2.) It's a fic series, and in the second part, Pepper realizes Tony has set things up so if he dies, everything goes to her. She gets upset because she hasn't said "I love you" to him yet, and while Tony doesn't mind, she does mind (or at least thinks Tony should care more).
3.) Pepper/Tony/Steve fic - towards the end of the fic, after some threesome sex, Pepper and Tony start talking/planning something, and Steve thinks about how he's sleeping with people who multi-task during sex. (Search #2 eventually turns into Pepper/Tony/Steve, so these two may be part of the same series, but I'm not sure).
4.) I only remember one scene from this fic. Basically Natasha gathers the team together because she needs help 'finding someone', but when she hands out the file, Steve sees Bucky's picture and thinks it's some kind of sick joke until Natasha explains about the Winter Soldier.
And, while not a specific search, I'd also love any fics where Tony and Pepper either get married or are married (or at least as good as married).