Book = text (+ images) + layout.
If there is only text and if its not an issue to position precisely your text then Libreoffice should be fine.
If you want to mix text and images, and have them precisely related and precisely layed out in each page, then Scribus will be better.
Its better to have the text 99% ready before begining the layout. I usually use Libreoffice for linear text editing. For this text work, i dont want images and layout to interfere with work on the pure text. When the text is allmost ready, i pour it into scribus along with the images and there begins the layout with precise positionning and graphical design.
Same for your corrections :
If you want your reader to check the quality of the text, then libreoffice is the tool since it can produce PDFs.
If you know your text is ready and you want your reader to check the quality of the book when it is allmost ready to print, then scribus is the way to go because it produces the PDFs that will fit your printer's expectations.