You can check the best practice on how handling position management in SuccessFactor including promotion, hire and termination.https://help.sap.com/docs/SAP_SUCCESSFACTORS_EMPLOYEE_CENTRAL/cf23ba26985f4d4a8df3a34b7392847d/1b5243de0d934e98890872312d5e...
Talent pool is just a group. Recruiter need to add candidate manually to the talent pool.You might consider 2315829 - Restricting the visibility of an application field to candidates - Recruiting Management https://launchpad.support.sap.com/#/notes/2...