Yes, Vivo V5s does have support for OTG.
Vivo V5s has 3000 mAh battery which is non-removable. It offers talktime of upto 12 hours on 3G networks and standby time of about 270 hours.
Yes, Vivo V5s is a true 4g volte mobile phone.
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.