any ideas on the most painless and cost efficient ways to return to the east coast of the USA from Naples without many delays and fight changes?
Did you already search flights to see if any direct flights exist from Naples (and which city pair)? The east coast is vast. Look at www.itasoftware.com for options - leave travel dates flexible. I don't think anyone on this board can guarantee lack of delays - the airlines themselves can't.
Meridiana/Eurofly operates a weekly flight from NAP to JFK. It is also seasonal only (check the Meridiana website). That's the only flight to North America from NAP. All other options require a change in some other EU hub, such as Rome (with Alitalia), Munich & Frankfurt (with Lufthansa), Paris (with AirFrance). Most flights to/from Naples are otherwise Low Cost European and Charter carriers.