I can't see it very well but it looks like this last image show the correct roof.

1. Considering your first request, the borders to fallow the sloping walls, I think was already solved.

I meant the inclinement of the border following the slope of a wall, not the texture alignment, that is indeed fixed, very nice!

2. In your specific construction it appear the faces 2,3,4 are part of the same plan. The faces 5,6,7 are also part of the same plan.
So, the program will treated as a single face.

That might appear so but they are not, at least not in the result that is wanted and as I created with shapes. Maybe 1 and 2 could be considered in the same plane since both have the horizontal border and are next to each other but there are definitely 7 separate segments. (They result in 8 faces if you include the vertical back but since it should be invisible I didn't bother creating an invisible shape for that [:))] )

...don't invent faces where don't exist edges;...

Yep, that's the problem I mentioned. To generate the correct roof there are 4 extra faces needed but there are no edges on the room to create those. The 4 extra faces needed are the ones against the bottom edge of segments 3,4,5,6 that can be set to 90° and made invisible as shown in this image:

Maybe this view helps to determine how an edge or face could be added. Perhaps when a point is elevated automatically add a point at the original position thus creating a new face.

I try to modify/add/remove points (one at a time).
Unfortunately is not so simple as it looks.

I believe that is not easy!

Wasn't there an option for extending the roof outside the room?

It is still there and is extended to 179 degrees over the room edge.

Where? How? What I meant was enlarge the roof so the borders extend away from the wall creating a small overhang. (and have a third option besides vertical and orthogonal: only the bottom border orthogonal with the tops closed)