Thanks for all this useful information!

I checked the tour itinerary in more detail than I had read it before the first post. Our last night will be at the Jordan Valley Marriott near the Dead Sea, about 30km southwest of Amman. The tour operator offers transportation to the airport after breakfast, too late for the early morning flight to AQJ. How does this change things? I checked the bus site you recommended; they seem to have service to Amman from there and then onward to Aqaba, presumably on a different bus. I should probably also check with the tour operator to see what they recommend.