Hi Ralph,
"When I insert a page break before the section break, the image on the first page of the following section moves down a page and that page is now populated with text from below."
Guessing here: when a section ends on a right page, and the next is required to start on a right page, it appears that Pages inserts a 'virtual' page between them. That would explain your not being able to put anything on it, and could also explain the images moving when an inserted page break (or additional text above the section break) causes generation of a 'real' page to replace the 'virtual' one as soon as there is any 'text' (including an invisible character, such as the section break) on that page.
In the Inspector, all of my images are “Floating (doesn’t move with text)” and “Object causes wrap” is checked and the last box is selected. Text only appears above and below all of the images.
'Inline" images are pinned to a specific location in the line of body text that runs from the top of the document to it's end. If that position in the line of text changes with respect to the document, then the object moves with the text to the new position. 'Floating' images (and other 'Floating' objects) are pinned to a specific location in the document—'this far' below and 'that far' to the right of the document's 'Home' location (top left corner). It's more complicated than that, actually, but 'this far' and 'that far' will serve as a first approximation.
One more bit of info: I did not use page breaks for many of my pages. New pages were created by using a Return or two at the end of the text on a given page.
Page breaks are needed only when you want to leave a large portion of the bottom of a page free from text. Otherwise, setting the "Space after Paragraph" and 'widows and orphans' controls will do a more consistent job of spacing text on a page. As Peter notes, it's generally a bad idea to use repeated spaces, repeated tabs or repeated returns as a formatting tool. My instructions to upper elementary kids learning word processing was to never press any of these three keys twice or more in a row (and to always press command-S when you were going to leave the keyboard). The command-S is less important now with most applications automatically saving (after the first Save, which gives the file a name and a location).
Also, FWIW, this document is very much the same configuration of a previous successful Pages project with the exception that I permitted text wrap around images in that prior document.
The button choice makes a difference only in the location of the area avoided by the wrapped text.
Regards,
Barry