How does this story deal with suffering imposed on some people in order for the majority to do well?
I think that this becomes one of the central issues that LeGuin forces the reader to assess upon conclusion of the short story. Essentially, does the voice of the majority overwhelm the suffering of the few? In a larger sense, we are being asked to assess if happiness can be legitimately derived if it comes at the cost of another's misery? The suffering of the child is something that enables Omelas' happiness. Leguin does not capitulate into simple moralizing. Rather, she evokes moral ambiguity and complexity, inviting some type of discourse and analysis as a result. I thin that the story deals well with raising questions in terms of how we configure happiness and suffering. I don't think that much in way of answers are provided as much as a sense of questioning and assessment is forced. In the final analysis, we are left with how to reconcile both experiences, one of the child and the other of the citizens of Omelas.
Interestingly enough, I think that there can also be some level of assessment of the third group of people. The ones who actually walk away from Omelas becomes another source of analysis here. It is suggested that these individuals cannot bear to witness over which they have no sense of control. Perhaps, there is a potential note of resolution here. Leguin might be suggesting that resistance to that which is unfair or that which pits individuals in impossible circumstances at the hands of others must be acted upon regardless of the consequences. The ones who walk from Omelas do so with a sense of guilt and pain that is impossible to eradicate. Yet, it is to this point where Leguin's work might be the most compelling. Regardless of the outcome, perhaps these individuals might find some solace in being able to advocate for the needs of the child even if the results will not be fully acknowledged. The mere act of speaking out against injustice is enough to provide some level of solace and assuaging pain in a setting where there is so much. It might be the progressive hope of continuing to fight for equity and justice regardless of consequence where those who walk from Omelas could actually walk towards a more transcendent end. In this, the story could actually help to provide some type of practical and workable solution to the issue of suffering imposed by those upon others.