In every table you have created_by_id and updated_by_id. These technical ids are not very helpful. It would be great if you could add the user table to which those fields are linked. This can be done programmatically via the newer “Data Query” interface from Zuora. Here are some links with more info:
-> User table: select * from User
If you would be able to see and analyze the actual Zuora user who created objects you could analyze things like how many subscriptions have been created automatically vs. manually and many more interesting scenarios.