Janine and Sara were working together in s1m9 "Distraction." The sudden need to do electrical work in the comms shack was not a coincidence. Janine took down the communications just as Five and Eight reached the chopper in case Eight had to kill Five. Janine and Sara both knew how attached Sam was to Five, so they didn't want him to be as traumatized if Five turned out to be an impostor. Sara even hints something along these lines.
The reason Simon was able to take down the snipers in early season 2 was because he was already immortal.
The mind control in season 3 affects dopamine levels. It makes ridiculous amounts of sense that early experiments would backfire and cause people to experience hallucinations and delusions, as psychosis is thought to be linked to high dopamine levels.
Back in season 1, there were hints about mind control in the D&D game where Maxine is talking about the Wizard Loki and armies of mind controlled ghouls or something similar.
