First of all, “mantain” and “craft” orders should be on separate columns to avoid clutter.
Second, columns should have a scroll bar (like the one to your right right now) to help you move through longer lists (and also avoid accidentally dumping items when moving downwards).
Furthermore, the ability to edit orders rather than always having to replace them with brand new ones. Like: double click = +1 of this order, right click = -1 (and delete when you reach 0). You could merge orders of the same item by releasing one on top of the other. And you could be able to move orders from one column to the other, why not.