Apparently the stuff can be used to overcome alcohol addiction because it induces hangover-like symptoms even with smaller doses of alcohol. You'll stop drinking if booze only makes you sick, I guess.Myb she was experimented on becos of that.
My thought is that Beniten's parents seem very loving in her flashbacks and they apparently hid her for a while, but the village was onto them and probably would've killed all three of them if they didn't get rid of her.I also like the memory that showed that beniten's father was actually a nice guy that cared for her. Maybe he wasn't even killed by tsukiyo, but the villagers. However, didn't beniten's mother try to kill her in one of the flashbacks? Maybe that means that the mother betrayed both of them or something.