Can I download an entire map portion rather than segments on screen

The printout only works with what is currently visible on the screen. One useful trick is to rotate the map to match your screen  which is wider than higher. Also you can go to full screen ( top right button on the map), and use the background menu ( click the mouse and hold the ctrl key) to generate the image.  What you see on the screen might look small, but the image we generate can be zoomed in a lot once you open the png file we generate.