The best interview I’ve heard of Fagen is the Leo Sidran one. Fagen seems to really respect him from him and his dad’s musical background, so he really opens up. It’s lengthy. Also, Leo has a nice technique of asking him to clarify quite a few of his comments. He also follows up with good insights that he bounces off Donald for confirmation or clarification.
Regarding Becker’s chattiness, I think this speaks to the (my) observation that he was the more witty, cynical, sarcastic, ironic, etc, etc of the two. In the Shaffer interview Donald commented that by and large he would come up with the musical idea, and Walter would help fill it out and then provide the lyrics. And you can see that in his solo records’ lyrics, which are much more self reflective than the Dan.
I believe those taxi passengers were heavily curated.