I'd like the idea of more pursuit stuff. They could help to reduce the long pursuits that can occur. Furthermore, a roadblock could be set up in other circumstances, for example when you get the armed gunman call you can create a perimeter and have greater security.
You could probably use filler voices, I wouldn't mind suspending my disbelief if it means more callouts. Besides, there is a ton of voices available... just have em cursing at each other. Regardless, this mod is heading in the right direction.