Haha, not incestuous - at this point Leia and Luke weren't brother and sister - this decision was made a few years after the release of SOTME.
Also, I find it interesting that we first hear the term "Sith Lord" in SW:AOLS, but we don't hear it in the films until TPM...
And if the Kaibur crystals were being mentioned since SOTME, why were they NEVER used in the films? Seriously, Foster wasn't the only person to use it - Lucas did multiple times. It's weird...