If I change this sentence to "I am working for Emirates as a first class crew.", is "a first class crew" less emphasized?
That's a good question! In general, whatever is put at the end of a sentence tends to have less emphasis since it is heard last. So if you changed the sentence order here and put "first class crew" at the end of the sentence, it would slightly reduce the emphasis on "first class crew" and cause "Emirates" to be emphasized a little more strongly. However, this change in emphasis is very minor and the overall meaning of the sentence would still remain the same if you did this.