Does that mean he went after this information, or more likely one of the computers in the botnet happened to have such information residing on it. It's possible he didn't know of any financial information...
No it is not possible. Had you actually read the above references as you claimed you would know that after executing a search warrant the FBI found credit card numbers and SSNs on computers in his dorm room. It's in Section 12 of the FBI document. Sure, maybe that was a result of a chat room he was logging. Maybe he didn't specifically go after this information himself. But at the very least he still chose to retain that information on his computer and at worst he did indeed go after the information himself.