Yeah not all the companions have their skills implemented at the moment. Eventually they will all have unique upgrades for all their skills. And yes whispering bandits is a patreon quest at the moment. For the damage it's hard to say it might be a bug since they are supposed to be consistent (no rng), but different skills affect the armor and health differently, so it might be just that. We will add more description to the items, but you can safely sell most of them, except the gears which can be useful in combat and the food which regenerate health outside combat.