Yes, Vivo India does provide a complimentary protective case inside the Vivo S1 standard packaging.
No. Vivo S1 does not have the front camera flash. It has a display-screen flash.
Yes, Vivo S1 has an in-display fingerprint scanner.
No. Vivo S1 does not have the USB Type C port but it does have a MicroUSB port. The phone has fast charging support via MicroUSB port charging.