I just completed another campaign (the 4th one, that one HURTS), and at the end I could barely hear some audio during the cinematic. I keep music turned down as I'm listening for game audio clues, not the music. So I'm missing these and wanted to chime in.
Also, I'll also STRONGLY agree with the fact that the UI is disabled while the dialog boxes come up during campaign missions. This is very frustrating. I either click madly trying to get the dialog to go away or wait and take my lumps for the number of seconds it takes for it to stop. Perhaps a different presentation style like an RPG game's dialog where some text shows up and either has an X to close it or an arrow graphic meaning there's more to be said.
Lastly, an ability to go back through the dialog during calmer moments would be nice.
And one more HUGE congrats and thanks for an awesome game!