Page 7 should be page 8. Page 8 should be page 7. Everything else is fine. Dragging is overkill; range typing is fiddly. You want a swap operation.
Flint has it.
Click, click, swap
Open reorder PDF, find pages 7 and 8 in the thumbnail grid. Click page 7 (highlights blue). Cmd/Ctrl-click page 8 (also highlights). Right-click and choose 'swap'. The pages exchange positions. Save.
Or drag if it's faster
Sometimes drag is just as fast: grab page 7, drop it on page 8. Page 7 takes page 8's spot; page 8 takes page 7's spot. For adjacent pages this is sometimes quicker than the swap menu.
Multi-pair swaps
If two pairs need swapping (7-8 and 23-24, say), do them one at a time. Flint doesn't have multi-pair swap because it's not actually common — usually if multiple pairs are wrong, the underlying issue is something else (a sorting bug, a duplex flip), and a different fix is cleaner.
What happens to bookmarks
Bookmarks track pages, so the 'Introduction' bookmark moves with page 7 to its new position. Internal hyperlinks remap. Page labels (if used) move with the pages.
FAQ
Can I swap non-adjacent pages?
Yes. Click any two pages and swap. Distance doesn't matter.
Does swap work for more than two pages?
Swap is two pages by definition. For three or more, it's a reorder, not a swap.
Will swap affect rotation?
No. Each page keeps its own rotation through the swap.
Can I undo?
Swap again — same operation reverses it. Or click reset before saving.
Click, click, swap. Exchange two pages.