No. Vivo S1 does not have a notification light but it does have Always-on display.
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 Qualcomm Snapdragon processor but it has latest the latest MediaTek P65 octa-core processor.
No. Vivo S1 does not have a hybrid sim slot. The mobile has a dedicated MicroSD card slot. You can use a memory card of up to 256GB.