Yes. Or the host needs to eat a lot to survive.

No. They don't need the host life to live more like just their adrenaline, it's why most of the Symboites Peter we see are usually always moving. Now granted the MCU could always change this in the future but I doubt Sony would allowed them to do it lol.

All Symbiotes needs a host to survive

@IronWidowMaikuB is right in fact in no way home post credits scene a bit of venom is shown in earth 616 (or 199999) without Eddie Brock