I would say yes - but the Shaman would need to make the required caster level check each time Life Link would trigger, IMO.
Yes, CL check each time the heal triggers until one is successful.
I just got an odd character idea though after looking the Vargouille up... character could be stuck partially transformed, and only his heightened continual flame spell is keeping him from becoming one. Bald, bat wings for ears, tentacles, fangs. Yup.