If they're was confidential information coming through that server, it doesn't matter that it was an aide who sent it, because it was Clinton's private server, and as we already know, she did have confidential information on her server.
sure, but i'm not sure how that would change their recommendation if there were already confidential information that they found before. also, again, we still don't know if these e-mails contain any confidential information.
the most likely situation is that nothing happens, not because of corruption, but because this is almost certainly nothing unlike what was already investigated previously.