thanks for all the help. here is how it's turned out. I magaged to book
EZE-DFW-EWR-MIA-MAD-MIA-EWR-DFW-EZE
with stopovers in EWR both ways on AA.com for $1760.
still not ideal for me as I now have to pay extra for LHR (and actually need to go to ATH also) and internal Europe on non LCC is expense!! when you don't have ultimate flexibility, but it all works out as it would cost me $100 to get to JFK each way vs. free for EWR (wife would drop me

).
Also, for this instance there were no problems upgrading the B class as a full fare.
cheers