No. Oppo A5s does not have the 5G network support.
Yes, you can play PUBG on Oppo A5s. We recommend you to buy 4GB RAM variant of Oppo A5s for the better gaming experience.
Yes, Oppo A5s does have the support for the face unlock. Besides, it also has a fingerprint sensor.
No. Oppo A5s does not have fast charging support.
Yes, Oppo A5s does have the OTG support.