I live for the travel planning!
AF zed low CAI/CDG (about $65 each) you can catch the CDG/ATL DL flight for your backup (if you don't get the CAI/JFK DL) on the same day you arrive CDG--you have to go out to the tkt desk and check in then re-enter to DL gates but it only took us an hour total w/carry-ons
If the PM function is working, I can help via phone or email if you want.
I have alerted Abdo in Cairo to take good care of you. Fayoum is his hometown--if it interests you, that would be an off-the-beaten-path trip.