But it looks like quite a number of other passages might need similar
fixes.

Another thing worth mentioning is that in the presence of images, font
locking with different font sizes, proportional fonts and similar, the
wrapped column should certainly be the visual column instead of
anything else.  This means, for example, that it is completely useless
to insert a newline in the middle of an image: it only makes sense to
replace such spaces that have a different visual column.
Unfortunately, current-column does not take images into account.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum