Vivo Y95 does have the OTG support.
No. Vivo Y95 does not have the front camera flash but it does have the display screen flash.
No. Vivo Y95 does have a dual sim card slot and a dedicated memory card slot. You can use 2 4G sim cards and a MicroSD card at the same time.
Vivo Y95 does have the scratch resistant display but the company has not mentioned if its Gorilla glass protection or not.