OK, I have made a slight update... I dont' have time right now to do everything I want to. But this takes care of two usability issues (I hope).
There is now a check box that you can select that turns the control panel on and off. So, once you have the opacity set, you can turn off the panel so it doesn't obstruct the view as much.
And the F1 (Attention) button is now a toggle. It will put you in and out of the overlay mode. This sets up for the other changes which are coming (whereby you can flip through pictures and resize the image using mouse and keystrokes, etc...)
The new file is here:
Hope this helps somewhat...