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.
“When all Americans are treated as equal, no matter who they are or whom they love, we are all more free.” -Pres. Obama
"A great democracy does not make it harder to vote than to buy an assault weapon." -Pres. Clinton