Maybe one day, but there are the other 99 things on my list of jobs to do first.

A Blend Mode effect is similar to the blend modes used in PS or other bitmap apps to apply effects between their layers, only in this case it's between sheets. If you turn all the polygons mid-grey their shading will create a relatively smooth 'arch' without the fizzy appearance of any texture. You can then blend this to a nice simple rectangular polygon of a roof texture of your choice on an underlying sheet using a Blend Mode set to 100% opacity and Soft Light. Soft Light is a Blend Mode that will shade and highlight the underlying roof texture according to the shade and light of the roof arch.

You're welcome :)

Here's an idea to solve the problem of the textures. Have you thought of turning them all a uniform solid grey colour and then using a Blend Mode to Soft Light them all onto a new underlying sheet with the actual roof textures on it in two nice and simple aligned slabs of tiles or whatever you prefer?

You are almost there in your thinking towards the end.

Instead of drawing just two slabs how about drawing many strips along the length of the roof, using Shaded Polygon on all of them and then editing the pitch of the resulting strips. It's not as easy as I've just made it sound, but it's achievable. I made an onion dome out of shaded polygons once. You might pick up a few tips on how to do this barrel roof from the blog I wrote about it.

In the File menu you will find "Resize Drawing Area". This command will open a small dialog in which you can enter the new desired size of your map. When you hit OK the background, screen and map border should all stretch out to the new size, leaving your original map content anchored in the bottom left corner. If you want it placed centrally you will then have to carefully box select the contents of your map and move them to the new centre.

This command is very successful with newer styles, but since it is a new command it doesn't necessarily work that well with older styles, so it is as well to save a copy of your file before you try it.

If you have a resize error just shout again and we can guide you through the process of adding the relevant map note and making sure the screen, background and map border are all on the correct layers.