Hi Rick,
If you select the first Next Page break, change it to a Continuous page
break, and then delete all the "text between what *had been* Next
Page Section Breaks, starting from my current cursor position to end of
document", then you will not have any other Next Page breaks. Did you mean,
as you show in your pseudo-code to delete from the beginning of the selected
section to the end of the selected section?
"So the headers remain untouched". Well, by changing the section breaks, you
risk losing that. That is, when you change a Next Page break to a Continuous
page break, then (at a minimum) the first heading will not be until the
first page of the new section. (I hope this makes sense.)