Yes, Vivo S1 does have a 3.5mm headphone jack.
No. Vivo S1 is not a waterproof mobile phone. However, plenty of covers available for the mobile which can protect from sudden water splash.
Yes, Vivo S1 has an in-display fingerprint scanner.
Vivo S1 standard packaging box contains - Vivo S1, Earphone, USB Cable, USB Power Adapter, Protective Case, Protective Film (applied) and a user guide.