Also, it seems that you can't select a road when using the road editor with the map overlay. Or at least the outline doesn't show up. You have to pre-select a road, then open the overlay for the lines to appear. And it doesn't let you select a different road either.
This what u are saying is very important. Because the tool is so great, but without the posibility of doing that, can be useless much times. For example i wanted to build a "road" for make some lines (are water torrents) in a known mountain near my place.
As long as we still dont have tools for modify that (i am sure in the future the engine will have tarrain modificator for users), i though in make those torrents with roads. Using that map. But here are the problems...
When you select roads and then open the map, you cant modify that map (or i dont know how). And also, you cant change the map for use photo satelite option, so i cant see the real terrain, and i also cant use the zoom so i cant go to the place and build the roads i want.
Also as Jagerbomber said, you cant choose the road builder when you have the map opened.. Then you also cant put the satelite and use the zoom, and then open roads.
Then in any both ways, you cant use that map hability for build roads on photo with zoom.