Yes, LG Q6 Plus does have the face recognition. You do not even require to power up your phone. It's camera automatically detects your face and unlocks the phone more quickly than typing, drawing or fingerprinting.
No. LG Q6 Plus comes with 1.2 A power charger which is not fast charger. But you can use Sony CP-AD2 USB charger to charge LG Q6 Plus faster.
No. LG Q6 Plus does not have the fingerprint sensor but it does have the face recognition lock.
Yes, LG Q6 Plus does have the VoLTE.