Thanks for the feedback. I like the idea of the Buddhist undertone to the end of the series. It seems to make sense with how things work out. I'll offer another interpretation.
Lain's monologue in the beginning of Episode 13 is her coming to terms with the way her physical body has another "voice" inside her head. She's not really aware of it at this point, but knows that something is wrong.
Lain is the first person to become "conscious" in the sense that we know it. Throughout other episodes, we see people who do things and don't understand why - take the shooter in Cyberia as an example. He's seen the "Club Lain" as an abstraction (a god) and doesn't really know why he's doing what he does. It's just a voice, or command, in his mind. This is the first time that we see the ability of Lain to affect the real world by being present in the right brain. When she speaks to him it drives him mad, outside of the Accella.
All that being said, I can't argue against the Buddhist interpretation either. Good post.