I'm happy you've read and follow my recommendations.
Are reflected on the results. [=D>]
For the sides of the dormers you need some sloping walls.
You could calculate or you could approximate it visually in 3D view.
Personally I use the approximated measurement for the start and after that I perform accurate calculus.
For the roof windows you could simplify the task using the special library in place to made the hole manually even this it is possible.
I know I've write it in the manual but, meanwhile was released 4.5 and the roof windows library to simplify this task.
Don't let us (GRT) to think we work in vain for this. [:(] [;)]