The current drag/drop mechanism for adding questions is not just tricky - it doesn't work properly. MANY times I add questions to the bottom and they appear in random places near the top of the assessment. Using a mouse it's hard... using a trackpad it's virtually impossible. My suggestion is that if drag and drop can't be implemented correctly, a simple "Add New Question at End" button is added, or the old "up arrow/down arrow" style of reordering is implemented. This could easily be done in addition to drag and drop, or as a replacement.