AA JFK to FCO direct is a very nice flight. AA BCN to JFK is also very nice and very direct. I caution on use of IB where you have to change plains in a large hub airport such as BCN or MAD. We missed a connection at MAD - details to long to go into here - check IB board.

Coincidentally, I just booked a 50k Business class from JFK to BCN in July 2012 for my wife. Now I just got to get earning so I can get her home again !

Also, from your routing, it seems like you're working against the geography of our humble planet by flying through ORD or LHR to get to Rome (from ATL or MIA - hard to follow). Go through JFK.