Concerning the books textures. I have worked out an easier way to correctly map simple textures like that. I don't use Blender. Instead, I take the original texture and import it into Sweethome3d. I size it in the editor, making note of the dimensions. Then I add a box and resize that to match the dimensions of the texture. Then I apply the texture. Then I export the box as an object. Then I can import it into Blender and place it on the bookshelf as I want it. Repeat for the other books. When all is as I like it, join all into a single object and export as object format again. Then import into the Sweethome3d Library editor. It will come in with all textures correctly oriented. [:D]

Easier? Seems overly complicated for my taste. I can't imagine doing that for every single of the roughly 80 books on the shelf. That must take forever!
If you do it in Blender you can use one image for all the spines on one shelf (or even several shelves at once). Use the image as background in Blender to get the size of each individual book spine right - no need to take note of book dimensions.
Then unwrap all book spine faces at once and correct the resulting UV layout by exactly placing the faces on the texture image.
The tedious part is not actually the UV layout itself but the placement of the planes for the book spines on the background image.

I must admit that it takes some effort to learn how image textures work in Blender. But once you get the hang of it you quickly start to appreciate the possibilities it gives you.

Best, slimpy