I think the crashing is caused by the #default material. On a fresh sketchup file, if i create a scene without applying #default rich section material to random object first, the sketchup would crash after creating rich section.
And about the 2 scenes, I couldn't get it work. I couldn't make the option to create 2 scenes automaticaly for each rich section to work. There's only one option available on rich section setting for "Scenes created for each richsection" : Scene, sectionplan visible, no camera applied.