How do I show an interior elevation if the interior of the room is not rectilinear--for example, if the ceiling is sloped? Otherwise the interior elevations just look like sections.

Also, is there a way to make the outline of the elevation a thick line, regardless of what object is being cut?

Currently I have been using the invisible line tool to get rid of undesired lines that remain within the rectangle of the crop region, and then adding Wide drafting lines onto my sheets over the perimeter of the elevation--certainly very low tech.