When Vivian's ult is up, combo your Fire Spit and Salvo on her. The AoE damage will seriously hurt her and her ult drones, if not outright kill. If you can't get close enough, poke her from a distance.
Be very careful of Khan ult, as if Inara gets thrown off the map, she has no way to save herself. You can use the Mother's Grace talent to give him fewer chances to attempt to grab you, otherwise play carefully with lines of sight.
In a straight DPS fight, Vivian does more damage than Zhin. If you have Deflector Shield up, you're likely to win the 1v1. Be wary of his ultimate and Whirl, as both will ignore your shield and the latter can place him behind you.
Shell spin through his potion to dodge damage and CC. Jump from side to side when you see him try to throw his snake. Damage him and hook him for the finisher, even if he uses his escape you should still be able to get him.