I don't have a problem with "orphan" models, but that is because I never change the "name" on the file until I am ready to create its item.
That makes it very easy to spot where I last stopped. I think for folks who do have that problem, being readily able to ID that situation would help.
While I loved having the black side menu always there, I have to admit that having more room on the screen to work on creating the item is nice. And the Shop Inventory page looks cleaner. One thing I noticed is that if I increase the width of the browser past a certain point, it doesn't expand; all you get is more white space.
The expanding the browser also reaches a limit on the shop side. For my customers, the factions on the side are very important. At a certain point, neither the titles of the items add letters nor do the category names. All that happens is the left adds white space.
I suspect this site might look better to a mobile device user.