I looked at the dpa_project table, and was expecting xml or something in the project_data field, but they're all null. Also, I couldn't find a linked table with anything that looked like xml or legible content to query.
Is there a field I can query/retrieve this information?
The project_data column appears null because your projects are stored as XMLs. Your projects can be found in [Install Directory]/userdata/projects. They are not null when the Projects are made in an Agent, and Agents store their data within the database.
Restoring the userdata folder would also be necessary for your backup. When you navigate to that folder and open it, you will find all of your essentials in this folder.