Relative path vs full path for images and PDF links

[Carlos]

Correct me if im wrong but another way would be making a plugin with a simple form on the backend (old path field, new path field) that searches/replaces all the old paths with new paths directly in the xml files(?).

Yes of course, I even suggested something like that in that other thread.
(But I thought it could be interesting/useful to have a plugin like this FixSiteURL)