|I’m not sure I understand you correctly, but when you say:
“dpkg might ask you questions about the setup of a package.”
Are you referring to what happens during a package installation where the whole process pauses and asks the user some questions?
In that case, it is actually debconf that is responsible for the interactivity. It is a matter of configuring the package correctly during install. This behavior can be changed by configuring debconf to make more/less assumptions.
DISCLAIMER: I’m not a Debian developer, just a user/admin since ’98 (other UNIX since ’94).