Yes, Vivo Y83 Pro is a VoLTE mobile phone.
Vivo Y83 Pro has the same aperture of f/2.0 on both sides of cameras.
Yes, PUBG requires at least 2GB RAM and can run on Android phones with Android 6.1 and above. Vivo Y83 Pro has 4GB RAM and it is Android Oreo device. You can easily play PUBG game on Vivo Y83 Pro.
No. Vivo Y83 Pro does not have the fast charging support but it comes with 5V / 2A power output charger, which charges the phone quick.
Vivo Y83 Pro has a scratch resistant display. However, it not confirmed by the brand that if it is Corning Gorilla Glass or some other technology they have used.