HI @ajackson, you are on right platform,
we have ability to do all above things which has been asked by you.
- ODK Server you can make an admin account which can export, edit data in CSV file.
- Supervisor with the help of an android app can assign interviews.
- Data Collector can be collect data on their android phone.
All things can be done with the help of ODK. If you need any help you can ask more things with me.