1). The service center's email was hiden by the Congresswoman's staff', so I cannot give to you.
2). Tell the office about the EAD renewal including application submission date,receipt date, expedite request date and confirmation number,A#, and employer's letter.
3). I sent out the employer letter this Friday. They might not receive it yet, so I don't think it is useful.
4). My case was approved before the Congresswoman's email, so I believe that you should request the expedite process through the SR call and follow the process provided by one of the post in this forum.
Good Luck!