I think there should be a “select all” edit option. Like, a frame that could select one group of information to edit and resize and/or a select all as in select every single item in the Prezi. That would be great.
The ‘frame’ is already there: just press SHIFT (and hold) and draw a rectangle. Everything completely within the rectangle should be selected, and should obey the ‘commands’ of the prezi (also very handy way of selecting those nasty flv/swf files that are otherwise sometimes difficult to select).
If you press the home button, and even zoom out a little more, you can easily draw a rectangle around all the content, and do the same thing.
(Fellow user, not affiliated with the prezi team).