The ability to modify a location's size by the pixel while holding Ctrl and using an arrow key, much like with moving units by the pixel, could be useful.
Ctrl + arrow to move the entire location 1 active grid. Shift + arrow to move the top left 1 pixel. Alt + arrow to move bottom right 1 pixel. Otherwise, skip the alt + arrow and make it just control, treat it the same way as units. We can always manually set it via the properties box. We also have ctrl + alt and ctrl + shift, and ctrl + alt + shift to use. It would be nice to have uniformity when it comes to placeable objects like locations, doodads, sprites, and units.
If possible, could you make locations which are created with the snap to grid function create in units of the grid -1? When you make a location in SCMDraft (and staredit, actually) on a 32x32 grid, in, say, the top left corner, the coordinates will be 0,0,32,32. That makes a 33x33 location. The location boundaries are also confusing. It looks like on a 0,0,32,32 location that the location includes 31,31, but doesn't include 32,32, when starcraft will include it as being in the location.
The top location is said location (0,0,32,32). It LOOKS like it doesn't include 32,32, but it does. The middle location is how it SHOULD look. The bottom right square is what it looks like when you draw the location, which is correct. Hopefully you can make it so that both selecting and drawing locations look the same, just with the drawn one bolded on the inside and red.
"Parliamentary inquiry, Mr. Chairman - do we have to call the Gentleman a gentleman if he's not one?"