Yes, Vivo Y83 does have the e-compass.
Yes, Vivo Y83 is a true 4G VoLTE phone.
Yes, Vivo Y83 does have the 3.5 mm headphone jack.
No. Vivo Y83 has 2 slots dedicated for SIM card and a separate slot for the MicroSD card. You can expand phone storage by up to 256GB with the help of the memory card.