Is there a way to add objects (via recording, plus icon or any other way) directly to a shared OR without the need to copy each time the objects from the local to the shared OR?
Yes, with the object repository manager. Open the file. Select enable editing(under file menu) and you can add objects there.
You could also use Navigate and Learn option to add multiple objects to shared OR.
Winds of Change
you can open both the local and shared OR using the OR manager & than you can perform copy action from Local to Global/shared.