Here are some choices you will have to make.
Each page could have a head and subhead (everyone please stop telling me about "headers." I just mean "head" here in a graphic design sense.) or might not have one.
If this head and sub-head are to be separated from the text flowing through the document, have a (more or less) fixed position on the page, and are to be changeable from page to page, they will need to be put into independent floating text boxes.
A floating text box's location is defined by its position relative to the top left corner of the document section. That position is fixed until the user changes it. The position may be locked, but doing so also locks the box's content.
A floating text box will maintain its location, but will not display if the page on which it is located does not exist.
Word processing documents create new pages on the fly. A new page is created when the text stream requires a new page. If the text stream is shortened, and requires fewer pages than before, then the unneeded pages disappear.
So one possibility is to create a 10 page word processor document containing only nine page break characters in the text stream.
Set the Page Headers and Footers as tou want them.
Then place a text box inside the margins at the top left corner of the text field of the first page. Enter and Style a dummy header and subheader into the box, then size the box to fit the width of the page (or the maximum width of the text expected in this header. Ensure that the Wrap property has been set to wrap text around the box.
Copy the header, then scroll down and paste it as a floating object and position it at the same location on each subsequent page.
(SEE NOTE below re: Capturing pages before next step.)
Click in the text layer, select all, then press delete to delete the nine page breaks.
The document will drop back to showing only one page, with the Header/Subheader text box. As text is added to the text stream, new pages (with a copy of the Header/Subheader text box will be added as needed—up to page 10. When needed, page 11 will be added, but will not contain a text box.
At this point, the user can either
Select and Copy one of the existing boxes, then paste it onto the new page as a floating object, and position it as needed,
OR
Insert a new Section containing a new set of 10 pages,
move a block of text beginning near the end of page 10, and continuing to (but not including) the section break at the end of the current text stream, into the new section (this should result in the current page 11 disappearing),
remove the Page breaks from the new pages, and remove the section break on page 10, then
carry on as before.
NOTE: In order to be able to insert the new section/set of pages, it is necessary to have Captured this set of pages at the point in the instructions indicated by the "SEE NOTE" above. Capture Pages is in the Advanced section of the Format menu. Choose "All Pages", and name the capture "New Set". It will be added to the Sections button in the toolbar.
There is a linked text box (the default one, I can't figure out how to make my own or get rid of that one) that flows through the document. I have a footer, with a company name and address, and a header, with a company logo, that remain in place throughout the document. What I want is an editable text box, that is positioned in the upper area of the template, and can have a head and subhead entered into it, or not.
No time to add comments on this part, other than Linked Text boxes are unnecessary in a word processing document. They are used to flow text from page to page in a page layout document. But in a Page Layout document, each page is a separate Section, something you indicated you wanted to avoid.
Regards,
Barry