No. Comio C2 does not have the fingerprint scanner.
Yes, you can use 2 4G sim cards in Comio C2. But at any given time only one sim card will work on 4G network.
No. Comio C2 has a dedicated MicroSD card slot. You can use 2 sim cards and 1 memory card at the same time.
Yes, Comio C2 does have the front camera flash.