While, ostensibly, this scene is important because of what it established between Cirus and Asuka, it's actually more important as the first time we get to see Cirus' actual personality exposed. His 'inner monologue' is very much a characteristic of my own, and you'll notice it several other times in the story. I usually just use it for humor, but it's also a handy narrative tool in certain scenes. One aspect the reader may already notice is Cirus' somewhat extreme drive to be respectful or docile around women. He's the very opposite of James Bond. Also, Cirus is handsome, I am not, hehehe. The conspicuous specificity Cirus demonstrates in the 'kind of relationship' he's looking for is actually foreshadowing. You'll consider it patently obvious later, so explaining it now would just be silly.
Beyond character interaction, I just love hinting at secrets I'm not going to reveal until some important scene later. The nature of Cirus' eyes is one such juicy detail. Misato is more nervous around Cirus because she, as the adult, as more understanding of what he might be able to do. Asuka and Shinji aren't really aware of what Cirus is as much as an adult like Misato would readily percieve. Until one gets to know Cirus, he makes him/her very nervous. Naturally, Cirus' inner dialogue or point of view helps curb that 'dark mystery' to a simple ignorance level and suspicion. The truth, of course, is a mixture of the two. He's not psycho, but no little kid, either. And, being such an Asuka-basher, I decided to give Asuka at least one scene in the spot-light, leaving Shinji and Misato blinking. Visualizing her saying 'I can be very pursuasive' always cracks me up.