No. Vivo V11 has dual sim card slots and a dedicated MicroSD card slot. You can use 2 sim cards and a MicroSD card at the same time.
Yes, Vivo V11 does have the dual rear camera setup. The primary rear camera is 16MP and secondary rear camera is of 5MP.
Yes, Vivo V11 does have the GPS support.
No. Vivo V11 has a mono speaker set up.