Robert Downey Jr on Pepper:
“How do we have it so she’s not going [whining], ‘Tony!’ and I’m going [growling], ‘Where’s Pepper?’… That’s the other thing that I have been pushing for. She’s in great shape, she’s really game. There’s all these genre movies and you have these capable women and they’re like, ‘Oh my god, some action is happening, I better step away or get caught in something over here.’ It’s like, ‘Really, is that where we’re at in the 21st century?’”
He also mentioned he was the one who insisted on having Gwyneth Paltrow in The Avengers: ”I was like, ‘You can’t just pretend that I got in a fight with Rhodey and Pepper’s out of town.’ They said, ‘You can’t have both of them,’ so I said, ‘All right, I need Pepper.’”
The Mandarin isn't a "Fu Manchu" stereotype:
The Mandarin -- unlike his comic book counterpart -- isn't Chinese. Feige cited Col. Kurtz from "Apocalypse Now” as a touchstone for the character. "His nationality's not even clear, because he's shrouded in secrecy. But at some point, this field officer went nuts and crafted himself into the Mandarin, a warlord. You get to do the comic book, but you don't have to deal with the specifics of Fu Manchu stereotyping. We're not saying he's Chinese, we're saying he draws a cloak around of him of Chinese symbols and dragons because it represents his obsession with Sun Tzu and various ancient arts of warfare."
The Mandarin was actually meant to be the villain in the first film:
As Feige pointed out, Favreau announced, "I can't tell you much, but I can tell you the Mandarin is the bad guy," at Comic-Con in 2007. That didn't change until 12 weeks before filming, but his "Ten Rings" terrorist group still made it into the film. The Mandarin's name came up again for "Iron Man 2" and "The Avengers."
Source (There's more facts about the film available there but they contain spoilers.)