Duplicate check for Non-worker when entering terminated employee as retirees

Summary:

Hi,

We would like to know that if an employee is terminated in the system as retired and we want to enter them as non-workers with non-worker type as retirees.

1. Will the system detect (duplicate record check) that the person is already in the system and pull up the information from the previous record when adding as non-workers or do we have to renter the information from scratch.
2. If the retiree is paid through payroll, should we use the non-worker type as 'Non-worker paid' or 'retiree'? what is the impact of choosing the non-worker type and person type? What is the difference between non-worker type and person type.