How do you set up an employee when they are a re-hire? Do you change the start date?

I wouldn't. All I do is reactivate. But of you want them to be populated in your state mandated New Hire report ypu would have to enter a new start date when you reactivate them. Sort of messes with their history in a snapshot as a seasonal employee Ishtar be with you for 20 years but will never have a start date older than 6 months previous