I understand you are having trouble with the menu. Not sure what the inspector via Data is but can already tell you that the menu items within the nav bar cannot be selected through the Menu Manager.
I also see duplicate items… the only way to help you here is to see the blocs file. If you wish you can PM it to me and I would be happy to have a look.
No problem. Just note that you can simply re-order the items from the left hand side tree (dragging up and down) as well as duplicate and delete. Just make sure you save often.