This might be entirely off-base and less than helpful. Publisher is not the tool I would use to write large text-based documents that are intended for publication. If you're serious, you might obtain any free version of LaTex that comes bundled with many relevant packages, e.g., Memoir, geometry, etc., which provide total control over dimensions and produce truly publication quality galleys in a variety of formats, such as PDF, PS.
LaTex is free; it runs on a variety of platforms, Windows, Macintosh and a variety of Linux distributions. In addition, many downloadable LaTex bundles are included in many standard downloads that include some kind of editor, building software, such as TexShop, etc. In addition, dictionaries and hyphenation packages are also freely available, so if you're writing in French, German, etc., your document will obey the hyphenation and spacing rules for that language.
The "downside" is that you'll have to invest some time and effort learning LaTex. But, many online tutorials, such as https://www.latex-tutorial.com/, are available to help you.