In my opinion the Gus we saw in the flashback at the pool was way too wide-eyed, innocent and naive to have been any sort of player in Pinochet's government. His lack of experience in dealing with heavy people was obvious. He went about making his pitch the wrong way, he misread Eladio and the situation completely and walked into the lion's den completely vulnerable and powerless. He acted like he was talking to some angel investor interested in his app, not a mass murderer.
The South American and Caribbean governments were the deep end of the pool as far as machiavellian politics were concerned, they required ruthlessness and cunning that would make a mafia boss cringe. There's just now way the Gus we saw at the pool would have survived.
In my opinion the writers themselves don't know Gus' backstory beyond the fact that he was "someone" in Chile, and the hints we've gotten have been contradictory.
-when they threw the word "generalissimo" in there I thought they were going in that direction.
-after the flashback at the pool I thought someone in Gus' family was big(possibly he was related to Pinochet himself) but that Gus wasn't involved in any way, he was probably sent to the US to be schooled. That's what the elites of foreign countries do.
-then there's the story in the latest season of BCS which reveals he grew up in El Chapo levels of poverty, so there goes that idea.
I really don't know what to expect. I don't think we'll ever get a clear story.
