A)thats up to you
B)possibly
although i do have to leave soon
C)suzaku and lelouch go way back
so do nunnaly and suzaku
and yet the first person he ever willingly opened up to abou his darkest secret was kallen
and she KEPT his secret despite them being enemies (revealing that he is resposible for japan's fate would have destroyed any hope he would ever have of getting the japanese people to accept him and his way)
she also kept quite about what he did to her when she was in prison (which would have, at the very least, destroyed his relationship with nunnaly)
and she is now keeping his secret about being zero
all of which he KNOWS
which is why i think she's actually a good choice for him to confide in, she already knows MOST of his darkest secrets ANYWAY