Hi Donjo, I think the confusion is what is your question?
Yes that sounds about right for the quantity of miles and amount of surcharges / taxes that you will have to pay. What others have suggested is ticketing to other destination on the Emirates network such as CAI being the final destination and DXB as a "transit" point which could bring the price of the ticket down but obviously with the added hassle of having to go there.

You can consider redeeming on AS but I don't think you can transfer from Amex to AS