As you can see in 3D, editing the pivot line adjusts the geometry of the roof plane and of the adjoining planes as needed:
Below, we have added an extrusion to the roof using the Add to Polygon editing command of the pet palette. The resulting roof geometry is modified, with each roof plane adjusted as needed, and the roof remains a coherent single element.
You can also modify the roof geometry by grabbing the ridge line at either endpoint or anywhere along the ridge line.
For a multi-level Roof, use pet palette commands from the selected level line to edit the vertical position or geometry of the Roof level.
Any skylights in the modified Roof will adjust themselves to the new Roof geometry, and will remain anchored to the plane depending on the skylight’s constraint setting: either vertical or horizontal.