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The recommended structure for creating and keeping track of Help Desk tickets would be to utilize the Cases and Activities tabs, however customers many a time customize screens/processes to their liking. The Solutions would also be very helpful, you can post internal documents as well as published documents for Customers/Contacts/Vendors/Employees to view through the portal.
When referring to non-licensed users, if you mean User accounts that have been created but not allowed to login, they wouldn't be used for the portal. The portal is used by Customers, Contacts, Employees, and Vendors, but in the QuickBooks sense; not using a Method User account that cannot login.
- Ashur