Yes, I was part of the design team that came up with the game’s plot. My favorite contribution was turning Vader into the unknowing catalyst for what would become the Rebellion. Prior to that, there was no real motivation for the Secret Apprentice to turn against his master, or irony that Vader’s plan would prove to be his final undoing.
Oh, and I made sure the Secret Apprentice died. Defeating the Emperor and redeeming Vader was the work of a new hope, an innocent.
And then, well, they brought him back to life.
Yes to both questions.
It’s plausible given the name, but it’s not literal. The LFE are something different.
An upcoming interview will detail this, hopefully in length.