@david --
Yes, it's a preference, but there's no way you'd lose if Move Selection was combined. If you want to redraw, redraw.
My mousing precision has gone down as I've aged, and it is as unlikely I'd get a selection right on the 5th try as I would on the 1st. Thus, my preference is to get a selection close, zoom in, and do fine adjustments.
@Crazy Man --
That's a good tip. But, keyboard shortcuts are really aimed at the advanced/serious user, and are not something the casual/infrequent user is likely to think of.
It's just not obvious to the new user what to do if they want to resize the selection.
Why not follow convention and display resize handles, especially if it doesn't alter the way experienced users work with the program?