Is there a script/report other than Page Access Tracking in Oracle Applications, or the below:
That can be run to determine what an FND_USER did between certain times he was logged in?
Apart from the above I believe there's not.
If you want to track data changes you will need to enable AuditTrail.
Audit features in E-business Suite (Doc ID 2002420.1)
Auditing: How Do I Audit Responsibilities and Data? (Doc ID 436316.1)
How To Track Changes Done On Oracle E-Business Suite (Doc ID 1262586.1)
Understanding Data Auditing in Oracle Applications Tables using Audit Trail (AuditTrail) (Doc ID 69660.1)
Trace is another option to see what the user did but this is mainly used for debugging issues and it would impact the performance.