

LAX-XIAMEN-TOKYO
Hi.
I am a mexican Citizen and i'm thinking of purchasing a round trip LAX-XIAMEN-NARITA with XiamenAir.
If i buy it, my departure would be on October 31st from LAX (11:50 pm) to Xiamen (05:30 am on November 2nd), and my Layover would be only for 3h 40m and then, i have to take a flight to NARITA at 09:10 am, also on November 2nd)
And my return would be on November 9th from Narita (02:55 pm) to Xiamen with a 2:30 hours of layover, and then, take a flight to LAX at 09:50 (pm)
Am I eligible for the free transit in Xiamen with this itinerary and holding a mexican passport?
And also, checking in Xiamenair Website, The LAX-XIAMEN-NRT Roundtrip is not available, and only by purchasing separately LAX-XIAMEN and XIAMEN-NRT. Do i have to make double check in in LAX and in Xiamen, or the airline connects it automaticaly? And if not, in Xiamen Airport, how do i leave the free 72 hour transit zone and make my check in again?
Thanks a lot!