No. Vivo V5s is not waterproof.
Yes, Vivo V5s does have hybrid sim slot. However, phone's internal memory is 64GB and you can also expand with the help of OTG.
Vivo V5s comes with latest Android 6.0 Marshmallow OS which has got Vivo's patented FunTouch 3.0 skin layer. Since the device is newly launched, we do not expect that company will release the new software update immediately.
Vivo V5s is just 7.55 mm thick.