I'm gonna try to get to everything in this one post, so it'll be long. I'm like Jacob on the subject, I kind agree what he had to say.
Charles/Rolo/Lulu/Marianne/V.V. theory
I'm gonna have to say that V.V. killed Marianne, but I think the parallel with Rolo goes deeper. It goes without saying that Rolo didn't just kill Shirley because he wanted to keep the "big" secret, but because he was afraid if Shirley got closer to Lulu, he would be pushed aside. V.V. could have had that same kind of jealous mindset and organized an epic cock-block. He shows obvious signs of jealousy/animosity towards her. When Orange-kun mentions her. When Charles says that he lied to him again, I think he was making an implication about V.V. masterminding the assassination and trying to come up with some excuse to justify it to Charlie-boy.
I'm not really sure about whether Charles loves Lelouch and Nunnally. Its debatable whether he is capable of loving anyone at this point after everything that he's experienced. I think that because they are the only children he had with Marianne, he couldn't bring himself to have them killed. I'm starting to understand him a little better, he's still an Alpha-dick, but broken dreams and being the ruler of an empire like Britannia can harden the heart.
Also, I believe Charles might have seen a lot of potential in Lelouch and sent him to Japan as a bargaining chip as a kind of test that would help him grow and mature into the ideal candidate for the Britannian throne. Since he wasn't able to succeed in his ambition to change Britannia from the inside, he kind of pulled the strings behind the scenes so Lelouch would rise up and finish what he couldn't. I'm not saying I have much more respect for Charles than I did before, but getting a better picture of who he was then and now, it does makes sense that he would do something like that.
Like illumi, I'm not ready to peg Charles as a good guy. This way, I can be sympathetic towards him, but still hate him at the same time. I will say that he is starting to garner a small amount of respect in my eyes.
Kallen/Suzaku and Refrain theory
I think Suzaku knows that Lelouch has his memories back, or at least has a strong hunch. He knows that Kallen would know if he did because she was with him when he first revealed his identity at Kaminejima island, so naturally he would assume that if he regained his memories he would keep her close. I'm not sure what he actually intends to get out of her directly by using Refrain, I think its more of an "in the long-run" plot.
He wants to know the truth and he knows that he can get it out of Kallen, but using Refrain is tricky because, as someone already said, it might not bring her back to events involving the Black Knights, it might have to do with Ashford or her brother. What he probably intends on doing is using the addiction as leverage to get information out of her. Being a recovering drug addict, its been a while but I'll always be recovering, I know how far a person can go to get a fix.
However, in using Refrain, it might bring up Kallen's underlying feelings about shit Suzaku was involved in that might be more than what he bargained for. In a sense, it might leave him with some kind of regret about the shit he's done. As much of an asshole is, Suzaku has the heart of a human and they are fragile things. He might have been living a double life when he was at Ashford, but at there was a time before he knew that Lelouch was Zero and that Kallen was the "Ace of the Black Knights."
Cornelia
I'm even more sure now that Cornelia is going to switch sides. With all the shit about Charles, V.V., and everyone else coming to light, it seems like Cornelia is being set up to play a serious role in the outcome. The fact that Orange-kun switched sides and his connection to Marianne, there seems to me as if its only natural that Cornelia would follow suit. There's still a lot of uncertainty about the details, but I'm even more convinced than I was last episode.
Anya
I'm still favoring my theory about Anya switching sides. She has that strange interest in Marianne and I still think that her Knightmare being named Mordred has some significance. She's a hard person to read. In terms of personality, no offense to illumi, but she is kind of Rei-like. I'm looking forward to seeing what happens with her.
Other shit
I watched 2 different subs for this episode. In Suzaku's conversation with Kallen about Shirley, in one he refers to Lelouch as a criminal and in the other I think he calls him "the white." That kind of caught my attention because of all the chess references in CG and the fact that in chess, the white makes the first move. I think its something that might be worth looking into.
There's something going on with Villetta and Ohgi. Not too much has been revealed, only that Diethard has been suspicious of him for a while and that Villetta is gonna try to meet up with him. There could be something going on with their relationship, but it remains to be seen.
I'm sure I missed a few things that I was going to mention, but if I remember anything, I'll make note of it.