No. Vivo Y95 does not have the NFC support.
No. Vivo Y95 does not have the front camera flash but it does have the display screen flash.
Yes, Vivo Y95 does have the portrait mode for both its cameras - rear & front.
Vivo Y95 has an aperture ratio of f/2.0 for its 20MP front camera. While the rear camera has f/2.2 & f/2.4 aperture for the 13MP & 2MP cameras respectively.