FYI I will definitely be flying in - driving from one coast to the other is never an option for my family and I live in Florida.
Someone told me only Carnival ships dock at Long Beach so I expect to embark at the San Pedro pier. But I would love to go to Long Beach anyway just to see Queen Mary's public rooms, which are still being used.
I always knew flying in on embarkation day is stupid no matter where your cruise starts because once I had to stay overnight at a connection airport and another time I missed my connection flight when the first flight was delayed. How long we stay in LA is still to be determined.