(1) The DNC emails upset Sanders' supporters as they demonstrated a bias in favor of Hillary. That drives down turnout. Also reinforced the notion of her being an insider.
(2) The thing with saying Papadopoulos was a nobody..was that he said turned out to be true. As for no one paying attention to him It's pretty clear if a so-called nobody told Don, Jr. there were thousands of emails on Hillary out here making her look bad...Don, Jr. would go looking for them. And it's not quite clear he was a nobody. He was one of the five members of Trump's foreign policy team. That photo you talk about was from the only meeting of that group. When he sent out an email to other senior campaign officials about coordinating meetings with Russia, apparently he was shut down by senior campaign staff. But if he told an Australian diplomat that Russia had dirt consisting of thousands of emails relating to Hillary...he almost certainly told senior campaign staff about it, too. We're getting the information that he was a nobody from Trump officials, who have every reason to minimize his involvement. His fiancé says differently: " Papadopoulos' fiancee, Simona Mangiante, told CNN in a recent interview that Papadopoulos was anything but a coffee boy. Mangiante, who explained she spoke out because Papadopoulos could not, said he worked with senior members of the Trump campaign. "He worked with Michael Flynn during the transition, and he was actively contributing to the foreign policy strategies for the campaign," she said. "He didn't take any initiative on his own without campaign approval."
(3) I don't know why Manafort did not take a deal. One thing that makes it difficult that once you file federal charges it's not that easy to get sweetheart deals. Sentencing guidelines are pretty strict and prosecutors cannot just dismiss charges because they feel like it when there is evidence to support them. Easier to make a deal before charges are filed when the prosecutor can select which charges to file. So...Manafort probably cannot get that great of a deal; he's looking at a long sentence even if he talks. And if he talks...no pardon. So I think it's pretty understandable why he would keep quiet. Don't say anything, ride it out, and if Trump gets through it then Manafort will get a pardon.