Nice summary. One comment, markers should probably be handled by <use>
elements... like with cloning... so that there is just one marker
instance. If the user wants to change the marker (after converting to
"path" then the can lookup the original using Shift-D as with colones).

I tend to agree with this, even though it's not the default behaviour currently.

Mainly because I want as few side-effects as possible in this action, and it's far easier to unlink the clones rather than link them all together again.

Maybe we should group them together as well so they can be unlinked all at once if necessary?

-C