If one of us just so happens to remember something important while we're at it, or a funny thought pops into our head at the time...why not bring it up? We won't stop specifically to talk, one of us will just mention something and keep going at it. *shrugs*
We do our talking after. It's usually me inquiring to learn what went well for future reference. She never asks - I assume that to her if I have an orgasm then things must be fine - no need to learn more - too bad she isn't more curious.
We talk to each other all throughout the day, there's no need to talk during sex. I can't think of anything that would kill the mood faster than feeling him deflate inside of me because I wanted to solve a first world problem.
No, but we often talk during sex. Like have actual conversations about mundane non sex related stuff. It's kind of funny. It doesn't adversely affect our sexual performance. Also, this usually only happens when we first get going. When it starts getting hot and heavy we focus on the task at hand.