When you unsubscribe from QBO payroll "core" do you still have the ability to see the employee center? Are you still able to setup new employees and track vacation etc?

No, when you unsubscribe from QuickBooks Online Payroll Core, you lose access to payroll-related features, including the Employee Center, @clr3. 

You won't have access to the Employee Center to view existing employee details. You also won't be able to set up new employees or add payroll-related records.

You will lose the ability to track paid time off (PTO), vacation balances, and related data tied to payroll functions since these features are part of the payroll module.

If you want to resubscribe in the future, you are always welcome to resubscribe and refer to this article for the detailed steps: Reactivate your QuickBooks Payroll subscription.

You can always comment below if you need further assistance in managing your Payroll account.