Michael,
Right now we can "bind" things together just by having them all selected at the same time. You can then invoke the "move" command and everything will move together. If it were possible to select the background without being in the image command then you could move it along with everything else that was selected. At least, that's what it might look like to the user. Alternatively, if you could select external objects while you were in the image command, you could then move them the same way you move the background. Again, that's what it would look like from the user's point of view. Obviously, I have no idea what the internal structure and operations would be. (Although, having been a professional programmer for 20 years before I retired, I would very much like to understand it. I'd like to write my own macros and UI's. Where do people go to learn enough about your program to do things like that? I know, I know...totally different subject.)
Mark