@milowe
If the USPS package is still on the way, intercept that package and have it send back to sender so you can update your application and send the correct one.
Anything to do with RFE will really delay the EAD approval process so its best to avoid dealing with RFE.
If it has been already delivered, call USCIS and report that you missed your copy of passport. I think it depends on agent but they allow you to fax as well. If this is a renewal, then a copy of your previous EAD will do the trick and they don't require a copy of your passport.
Let me know if you have any questions.