I am trying to understand what API endpoints are used for to provide the same numbers for reports that we pull in the interface. The goal of this is to automate the reporting. Could the Analytics API cover off on all of these or are there other API endpoints that are needed for each?
All of the APIs you specified can be used to pull various data that goes into a given report, but the Analytics API will cover all of these use cases in a single API (instead of having to aggregate this data on your end).