[DNSB]

As far as I can tell, the docx file is using one style for the heading and one style for paragraphs. The docx file is using spaces to indent paragraphs. That is another task that should be done with a style so you need two styles. One for the non-indented paragraph and one for the indented paragraphs. As for the page break before The Book of Hymns, looking at the epub file, you have:

<div class="calibre2"></div>

with the following in the stylesheet:

.calibre2 {
  display: block;
  line-height: 1.2;
  page-break-after: always; 
  margin: 0;
  padding: 0;
}

I've attached a quick and dirty edit of the epub file.