Do users and assets have to be added/managed manually instead of from a feed from an HR Software Program, FMI Program?

Not necessarily. There are different ways to add users or assets into the system. 

• Automated - example: users loads through the UMP or Dynamic User Creation
• Bulk Upload - manual through the DMU, but you can make changes in bulk. 
• One-at-a-time - manual via the Forum web UI. Which works perfectly for one-off changes on single records.