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The Firefly fanfic Forward shows that when River is near someone who dies - particularly someone she kills - she gets a full blast of their last emotions, thoughts, and personal history in intense detail as they die - a sort of backlash from the "whole life flashing before their eyes" thing. This results in River not taking having to kill people in close very well....but also keep in mind, this includes Reavers.
Going by Konstantin's dialogue, it's been fifteen years since he and the Six tried to kill Jayne. That's fifteen years that the Mongol has had to run amok in the 'Verse....
Zoe was able to take down Wade by pushing her emotions aside. However, the Inducer could affect everyone else on the station. Including, possibly, Zoe's unborn child.