Swift is recommending that all children younger than a year can be used as food. He is using the facts to argue his statement and make it rational. He is exaggerating to emphasize a solution for poverty, as he is giving us the hint that poor children are consuming food that people need.
He is saying that the amount of food that could be produced from a child and the skin that could be used fashion is relevant information. This satire is very sharp because it compares kids with animals, and points out that children are not more valuable than pigs.
Neither, because the shoes could be made of velvet, in that case, then it is neither or if the shoes are not really made of velvet, it is a metaphor. it is definitely not a simile
You determine if the evidence is relevant and if it directly answers the writing prompt when writing your essay by seeing if any quotes are relevant to the question or explains or possibly gives any background.
