Hello, all.
I am going to ask some newbie questions.
I have a ticket.
AA607 ORD-LAX 2045 2305
CX881 LAX-HKG 0150 0725
CX6852 HKG-PVG 0930 1155 by Dragon Air

All in H fare. Now the third segment, I can not earn AA miles.
1) In ORD, can I just check in the first segment? Then in LAX, can I ask CX GA to change my ticket for the 3rd segment from CX6852 to CX368?
2) If it works for (1), can I use AC in ORD?

Thanks

yuchung5