The truss drawing is nice and your workflow is probably something I would have done.
Have you tried playing around with different styles for different views? You may be able to achieve the ghosted effect via xray mode without having to explode it in layout. Depends on the final look you need.
The only way I can think to solve the “too many back edges” issue shown in the “Typical Purlin @ Rafter View” is via stacked view ports. Here is my imagined workflow.
*Create 2 different styles one with back edges on one with back edges off.
*Create the scene you want to see and duplicate it.
*In scene 1 hide all the elements that you DON’T want to show back edges and assign the back edges ON style,
*In scene 2 hide all the foreground elements that you DO want to show back edges and assign the back edges OFF style,
*Save and send the file to layout
*Place view port 1 and configure it to show scene 2
*Copy view port 1 to create view port 2 and place it on top of view port 1 in the exact same position.
(I tend to assign each view port to its own layer so you can hide/lock them individually, which helps with editing).
*Configure view port 2 to show scene 2 in Rasta rendering mode,
*Turn the background off for view port 2 in the Sketchup Model > Styles tab.
That should get you the image you want. Whether its the best way to achieve it, i don’t know.