i'm kinda with doc on this… there would be very few occasions where i'd have to shuffle lots of pictures or content over various spreads. that's not to say there's faults with the workflow, its just not a situation which crops up often with me.
however, may i suggest some workarounds? the shortcut to go to page is ctrl J. for example, a pic and some related text on p3 needs to be on p68. group and cut the selection, then ctrl J and type 68; and then paste onto the pasteboard. now, grab the content which needs to be swapped and cut that, ctrl J and go onto p3 and paste.
another workaround is to make a library. same scenario as above, but move the content into the library rather than copy it. ctrl J to the destination page and drag the content from the library. delete the item from the library and then grab the content to be moved into the library and ctrl J to the replacement page.
the third workaround would be to use snippets. that is, drag the content onto the mac/windows desktop. this will become a “snippet” which, when dragged into the destination page, comes back in as the content which it originally appeared.
i think what is making the process so difficult is the scrolling from spread to spread, especially if high-res preview is turned on with dozens of pictures. using the goto page shortcut ctrl J will make short work of scrolling. alternatively, a workflow which works for me is to have my pages palette open on the left hand side using the full height of the screen. i turn the placeholders off (or the pages palette takes forever to redraw and slows the machine down something fierce) but it allows me to see about 19-20 spreads all at once.
i hope this helps. if you do find a script which lets you swap content between spreads, please post the link as it would always be handy.
colly