How to record in the system if employee is on leave (Leave of Absence, Maternity leave)

Summary:

We have an employee that is on long leave. We are not using Absence and currently don't have anything in the system to record this kind of leave. I've read that there is a Suspend Assignment action and we have this under Change Assignment. Is this the Suspend Assignment action that we should use for this kind of scenario?

What transactions can the employee do while she is on Suspend Assignment and what actions can be made against her profile as well?

Will her user account be deactivated and will the employee be searchable within Oracle HCM (for example if they are Line Managers)?