You chose affectual images involving group and singular portraits of people. They are media images for journalism and in design terms, could be useful inside a book, with the great captions that you have given them.
I wonder, are these images more of a "moodboard", or a collection of "ephemeral objects" and imagery that might inspire a book cover? If say, you're book was chosen by a press that gives you limited pre-made patterns and colours to work with, what shapes and colours might you glean from your chosen images? Have a look at the Pivot books for their existing book covers to see what I mean?