while the “Print” and “Print Preview” dialogs are open a rectangle of the printable area (= paper size minus unprintable margins) should be shown and being moveable over the model space.
The scale and in consequence the printout should take the printable area into account only and nothing outside as e.g. currently an undefined white space.
I was thinking the same thing. If necessary, I suppose this could be done in a print dialog box with a preview area to work in. Also, if you check “scale to fit” the rectangle could then be resizable, but locked to the proportions of your print area. I imagine, that would be more the mode for printing for perspective views.