Unmentioned thus far is transferring BA Avios to Iberia Avios. Your BA and IB accounts must both be open for at least 90 days and you may have to have some recent activity in Iberia (send some Amex to Iberia or pay a friend to). You could fly PHL-ORD/MIA on AA then ORD/MIA-MAD and MAD-FCO on Iberia. I couldn't get Iberia to price out the itinerary including PHL-ORD, but ORD-MAD-FCO in economy costs 27,500 Avios + €90.