I have experience with manual-brick-editing, also prints, i could modify your brick to have 2 of the same print on each page (one on print per page). Two different prints on the same brick is impossible.
False.
The UV texturing can relate specifically to a portion of the image.
If a print .png is sectioned into, let's say, 4 parts (512/2x512/2) you could assign a 256x256 of each corner to a different face, effectively creating a brick that has 4 different things on it, but from the same print.
And then there's movement offsets for 2 bricks which can also allow that, but it's harder to set up. Basically a brick would be the cover and a brick would be the pages. This will also allow different colors between pages and cover, and allow the cover to have a different print from the pages, but you need to get the offset right and when making the brick you need 2 bricks in the menu for it to function correctly. What could also be done but requires manual editing is to make the cover brick also have white pages. The white pages would be manually all put as "top" quads and basically if you put the "custom" pages with a separate print and color over it, the pages under it effectively disappearing thanks to coverage and culling, thus creating the "cover" brick the same as you have in OP and the ability to put a "pages" brick over it which would make the pages customizable.