[Quoth]

If even as much income as that.

PDFs are an end result that should be regarded as set concrete. The cake analogy is good. The material used to create a PDF is the editable source. The Adobe tool is pointless.

Edit in Word or LO Writer and simply export a ready to go PDF.
LO Writer can Save As in many editable formats. PDF is an export, a one way trip.

Oh and Open Office is dead maybe ten years. Libre Office is the current alternative to MS Word.

Workflow
Edit and proof a version (in ODT if using Writer) with no headers, no footer, styled headings and paragraphs on a small 4:3 aspect page size, so you can see if layout is stupid. Avoid tables and don't flow text round images. Anchor images as characters with no text on same line. Do extra Save As in docx for Calibre or MS Word. No extra spaces, tabs or blank lines. Use styles. Avoid tables.

Only import a docx to LO Writer, never use that as edit-save-edit version as it will convert on import and convert on save only edit in odt. Save As an EXTRA copy in docx when proofed.

Use Calibre (or sigil) to make an epub. Make any other format of ebook (NOT a PDF from the epub2, inc epub3 if wanted. Only send epub to KDP or Google Play. Epub and dual Mobi to Smashwords, never doc but they don't convert well.

You might need to look at CSS of images. Big ones might be a % width and height auto. All paragraph and heading styles will map perfectly in Calibre from docx styles to CSS.

Then Save As your final odt as a different name with page size suffix and set page size to desired size of PDF. Add headers, footers, page numbers etc. If for paper have Left & Right pages (or Mirrored) with a suitable inner margin for binding.
Save odt (unless in Word, then docx).
EXPORT the PDF.
Preview PDF on a big enough screen or 10" tablet or 10" eink.
Edit the wordprocessor doc if need be.
Add a cover if ePDF, NEVER for POD (paper). Real books use separate wrap file which is front, spine and back. The POD site will offer a cover template based on number of pages and paper thickness. This can be calculated.

Save the versions of odt (or doc) of file for epub and pdf as templates after deleting most of the content.

Never edit the content of the wordprocessor file for Export as PDF, only paragraph, heading and page styles. Edit the version for epub for changes. You can copy and paste entire odt (or Docx if Word) contents into the PDF wordprocessor source and may only need to change to change a few page styles.

PDF is a baked cake.