Just a general comment popped into my head. When I make maps, I find it really difficult to delete the scenery and often it ends up deleting the wrong thing. Why is it so hard? Maybe an improvement for next map editor...

I think you have to click to delete where you had originally clicked to create it. IE: if you created it at X100,Y200 you have to delete it at X100,Y200 or there abouts - otherwise it wont delete. Thus, clicking in the middle of the graphic is the worst thing to do, and trying delete on each of the object's corners is the best plan.