No. Vivo S1 does not have auto call recording. But you can use Apps available on the Google Play Store.
Yes, Vivo S1 has a dedicated MicroSD card slot. You can use 2 sim cards and a memory card at the same time.
No. Vivo S1 does not have the FM radio support.
Vivo S1 is available in 2 color variants - Diamond Black & Skyline Blue.