You may not have read the examples I presented. When only the left edge of a window or the top edge of a window is in the "wrong" position, it should be one step to adjust it.I used to think that until I realized it doesn't take anymore clicks to resize a window in OS X than it does in Windows. First I move the window to where I want the left side to be then I resize the lower right corner. I'd get the exact same thing in Windows by resizing the right side and then resizing the left side. Not hard people and certainly not something to make a thread over.
When you care about the right-edge position and the width (not the left-edge position) or you care about the bottom-edge position and the height (not the top-edge position), you can't move the window first because you don't know where to put it.
None of these cases involve edges that are off the screen. However, that's another case where being able to drag window edges would come in handy.
And while we are at it, why not let users hold shift while resizing windows to have them resize in only the horizontal or only the vertical direction, again following the model of objects in design programs? I don't know how important that is (I'd use it occasionally), but it would be "free." As saltyzoo, I, and others have pointed out, we're talking about features that would help some and be unnoticeable to others. Mac OS X is full of such features, such as option-dragging a window to move it without giving it the focus.