Regarding Manny's questions to Meche: He isn't looking for an excuse, he's looking for a logical explanation. At that point in the conversation, he's already checked the DOD computer, and seen that Meche doesn't qualify for any premium travel package. He couldn't sell her a ticket on the Number 9 even if he wanted to. But since she should qualify, Manny wonders whether he's missed something, so he begins to question her about things she might have done in her life.
I think this is the point at which the story becomes "bigger", in that it starts to become obvious that there's something awry which extends beyond Domino and the boss.