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 fingerprint scanner. It also has the support for the face unlock.
No. Oppo A5s is not a water-resistant mobile phone.
Yes, Oppo A5s does have the OTG support.