I have done this in my game for zooming in and out of the layout. You really don't need image points at all. Have your map sprite as a background and set the layout scale to zoom in and out.
I simply had if mouse real gos up change layout scale to ' current layout scale +1 ' and added a compair conditions saying the scale had to be larger than a number. Same with zooming out only reversed. doing this will zoom into the center of the screen.
The grab and scroll is a little more tricky but just say if mouse btn is down then set the scrollx and scrolly to mousex and mousey
I think that will work. My scrolling was done by moving the cursor to the edge of the screen but the above method should work.
here is a quick demo. Its rough but it is just to give you some ideas