No. Vivo S1 does not have the 5G network support. It works on 2G/3G & 4G GSM networks.
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.
No. Vivo S1 does not have the IR remote sensor.