I think you win the award for longest review. There were only four for this chapter, but yours more than made up for it! Some thoughts on your thoughts:
1. I think that Ella is having problems mirroring; she probably doesn't think she was really flirting with Carter like that. The other guys (like Jack) are probably a little skeptical about Will's version. After all, he is that dramatic guy from Malibu, coming up here to Palo Alto, and seemingly causing more problems.
2. Robbie is probably really feeling the burden of responsibility toward Jeanine because he has her power of attorney. When she gave him that, she basically told him that he was the one she trusted most, and put her confidence in him. I think that's clouding his judgment. Robbie's pretty loyal and stalwart, normally, so I can see where he'd feel that strong obligation to Jeanine. When you re-read Be-Rad, keep that in mind. I think you'll see that in his character even then.
3. I think the real reason that Robbie wanted to shut down the conversation at dinner was that he knew how ugly it could get, and he was probably really unhappy with the end-result of their visit. I'm sure that in his mind, it would have been a pleasant encounter that made Jeanine happy, and encouraged her to thing more positively. That it didn't happen that way would probably weigh pretty heavily on him, for the reasons I outlined above.