After PDF was annotated, saved and PDF closed I want to reopen PDF but I can not anymore edit it, can not select annotations, arrows. Any workaround?
Once you save an image in Preview the changes you have made become part of the image - i.e. they can no longer be edited. However, Preview does store all previous saved versions of a file. To restore an image to a previously saved state (i.e. undo recent changes) choose
File > Revert To > Browse All Versions. You can then scroll through all previous versions of the image file & choose one to restore. Best analogy of this functionality is the way Time Machine works.