Nice work Richard :-)
Under 0710 you have an improved ability to add pictures through a new menu item in Web Admin -> Files & Media -> Screen Saver this lest you navigate to a directory and visually select images for the screen saver.
That's going to be really welcome. I can see the beginnings of that in the current beta2, but I couldn't get it work well for me, and I certainly didn't want to add dozens of images that way, as you could only select each one individually and then click update.
That said, may the next order of business is to provide a button in the WebAdmin screen, that while you are looking at a directory full of images, can add all of them at once. Or is that what you meant by "visually select images"?