Concluding on characterisation and voice
All novels, short stories, poems and plays are about people: that's why we read them. Even if they seem to be about something else, they will be about people - for example a text that seems to be about nature, may actually about the way human beings destroy nature, or are made small and unimportant by nature.
Texts explore ideas by throwing opposing themes together so always look at how characters contrast. Look at how they are described and whether their words match their actions. Consider whether they 'sympathetic' (we are supposed to like them) or unsympathetic (we're not).
Above all, you need to listen to what characters say. Look closely at the dialogue and use your knowledge from the Spoken Language Study to see how characters reveal themselves though their own particular idiolect.