I made a reservation for my family last summer to fly American metal using BA points from TPA to China through ORD - cost 50,000 BA points per person. I am hoping to change the last leg so rather than going from ORD-TPA, we would go ORD-NYC-TPA, stopping for a few days in NYC.

What is my best option? If I change the ORD-TPA flight, I assume I am going to get hit with a $75 per person change fee. If we just don't fly the last leg, and book travel using another airline or using Avios, would any points be credited back, or would it just be lost points and possibly a fee?

If we wind up still flying AA, would they still charge us for luggage if we showed them the tickets from the flight from China (even though it would be a few days after that flight?

Any advice would be appreciated.