JJ Abrams has always loved his "mystery box" of secrecy. However, to date, he has never lied nor misinformed his viewers in promoting his projects. Combined with the denial of Alice Eve, I believe Khan is not Cumberbatch's character. Everything else is up for grabs.
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“The test of our progress is not whether we add more to the abundance of those who have much; it is whether we provide enough for those who have too little.” -FDR
God gives us what we can handle, even if we don't believe it ourselves.