What are the motifs in Slake's Limbo by Felice Holman?

A recurring idea in Slake's Limbo is survival. As a young teenage boy, Slake learns to survive emotionally and in regard to physical needs. He builds a routine for himself on a daily basis. He wakes up early to collect newspapers and resells them. He makes enough money to buy a little food. He has a job at the lunch counter sweeping and mopping in exchange for a good meal. Slakes learns to survive with the little money he makes at these jobs. He also learns to reuse discarded items. For example, he washes out old soda cans and fills them with water. He uses newspapers for a bed. He stays in survival mode the entire time he is in the subway. On an emotional level, he survives by observation. He observes people, but he does not get too close to them. He keeps at a distance for his emotional safety.