Here "lives" refers to the whole person. Alternate translation: "redeems them" or "saves them" or "rescues them" (See: [[rc://en/ta/man/translate/figs-synecdoche]])
These two words mean basically the same thing and emphasize how badly the needy suffer. These abstract nouns can be stated as verbs. Alternate translation: "those who oppress them and hurt them" (See: [[rc://en/ta/man/translate/figs-doublet]] and [[rc://en/ta/man/translate/figs-abstractnouns]])
Here "their blood" is a metonym for their well-being. The sight of Yahweh represents his judgment or evaluation. Alternate translation: "their well-being is very important to him" or "he wants them to live well" (See: [[rc://en/ta/man/translate/figs-metonymy]])