No. Vivo S1 does not have the IR remote sensor.
Yes, Vivo S1 does have a 3.5mm headphone jack.
No. Vivo S1 does not have Qualcomm Snapdragon processor but it has latest the latest MediaTek P65 octa-core processor.
Vivo S1 has 6.38 inches of AMOLED Full HD plus display. It is further protected with Corning Gorilla Glass 5 level of protection. The mobile has a 90% screen-to-body ratio and has 19.5:9 aspect ratio. Vivo S1 offers 404 PPI of resolution.