I think you need to wait for the I-485 receipt notice and hope that USCIS does not increase the fees from now till the day they receive your EAD/AP application. It would have been better to send it now.
You don't need an attorney to apply for I-765 and I-131; Many of us have done it ourselves multiple times. Take a look at the EAD/AP forum. There is a documents list along with sample cover letter and attachments. The first time you do it it may take you 2 or 3 hours. However, you can ask your questions and people will be able to help you out. You can get started now itself. In these many years, I have not seen any rejection of I765/I131. In the worst case, I have seen people getting RFE for photos.