Maybe I'm missing something, but I can't seem to find a way to mass add items in my shop to a new category. I thought doing a "check all" would lead to the category showing up in "remove items to", but I'm not seeing it.

Do we really have to go through the drop down menu to change the category for each item in our shops? It's kind of tedious and time consuming for something that should be a helpful way to sort items for us and others to quickly access.

yeah, you have to do them one at a time. if it helps at all, you can select the category from the dropdown list on the first item you're moving, then hit the tab button until the dropdown for the next item you want to move is highlighted, press the button of the first letter of the category name, tab to the next one, and so on.