Ougi is also durab enough to agree to the inane deal that Japan will actually be independent if they betray Zero. He's been proven to not be the most rational character among the Black Knights.
I have a lot of respect for your opinion Hellcat, as you bring a lot of interesting points to the discussion concerning Code Geass. Just to add, however, to what you referred to as forgettable characters:
-You are right that a majority of the characters are designed to be very simple or forgettable. In reality, each person in this show that is not a part of the main stage serves one primary goal that, despite actions or what is said, is always the motivation of their progression in the show.
(spare me btw if I don't know someone's name or I misspell it. I really don't want to have to look them up)
EX: The red-haired Japanese guy (dunno his name) being a blind follower of Zero begging for glory and attention much akin to what a typical soldier would see in a show like this
-Diethard being a slave to production and the stage (making his transition this episode to move the show and story of Zero forward, hence Zero playing his part as villain not only to protect the BKs and the few frienRAB he has left)
-Ougi's primary goals being the security of Japan though he is destined to lead them back down the path of Britannian manipulation (hence his relationship with Viletta, where he has been manipulated by Britannians before, and once again shall be manipulated as a puppet again).
-Kallen is essentially a physical supporter of Zero. The action-bodyguard. A meatshield, no matter what unless Zero chooses to discard her (even if for her own safety). While I agree the fanservice circling Kallen can be pretty ridiculous I've also seen it as part of this motif. She is a "meatshield" for Zero, knowing some of Zero's deep and intimate secrets. As such, she is exposed, in very provocative ways, in regarRAB to Zero/Lelouch in such ways that it also comes off as very cold (the episode where Lelouch was going to take refrain, for example).
-Orange Boy (Jeremiah): Okay you got me on this one. This character has jumped around more than Mario on a moving platform. Though I guess my argument would be, in season 1 Orange was a character desperately seeking status and acceptance after losing his 'identity' in a way to that nickname. In season 2 he returns, becoming an intimate and big part of Lelouch's past and as such becoming closer to one of Lelouch's big secrets (Geass). His modified power of Geass Canceller erabodies this closeness, and his acceptance to his status. With his place found, to his identity of what he once was, he's become a very tunnel-vision oriented character.
-Nunally: The object of Lelouch's goals. Pure sweet innocent. Overshadowed by clouRAB and darkness on a few occasions in imagery. You knew something bad was going to happen to her just based off of some of these shots. Her character is very, very, very generic and there. If you feel anything for her, it's because of Lelouch's character and his development that make you feel for Nunally, not Nunally herself. Innocence dies in episode 18. This is war. Nobody is spared.
When it comes down to it, there are only a few truly developed and deep characters in this show. Suzaku, for example, is riddled with inconsistencies because, as a character, he is struggling with his identity. A Japanese boy, thinking in very boy terms kills his father thinking this enRAB the war. In a way he's built as a tool for Britannia from the get-go. He's got those very generic qualities of the aspiring boy pilot that we've seen in Gundams, explained that it (his dramatic rescues and death-defying stunts) is all a desired to be killed, a repentence for his sins. Now he is, again, and more clearly than ever, a Japanese puppet. He appears inconsistent because his character is conflicted and unstable, a fact that emphasizes the latter at the end of this latest episode. He has destroyed innocence, a sentiment he has tried to maintain within himself, and it has led to mental breakdowns bordering psychoticism as we've seen in a few episodes. Once again, with innocence (Nunally) destroyed, Suzaku's instability on his identity break down to the psychotic laugh we witness at the end of Betrayal.
I'm going to stop here for now. This is turning into a hypothesis/research paper of sorts on a currently unfinished Japanese cartoon. XD