Thank you so much for the answers, Mark!

Now I know what the Clip in Shader Ops is for! I never had a chance to use it.

Thank you for the HDRI tips. The scenes I had in mind where indeed outdoor scenes, so it should simplify things a bit.

For the interior, though, I see that the spherical camera does have the lens zoom setting, but I don't see a difference in the renders when the setting is changes. Is it because the spherical camera ignores the setting, or do I need to check some other option for this to take effect?

Quote - Forgot the Vector line stuff. Compound paths and such import successfully as cross sections. They will not import as the wall projections. You can rotate the cross-section if you are using Pipline Extrusion. However, you can also simply select the cross section of your choice, select all points and use the rotation tool as well.

I typically save my .ai files as v3 for maximum compatibility. 

I was importing the path as a crossection. The image is attached. (Saving it as Av3 yelded the same distortion :(...)

For the wall projection(envelope/sweeping path), does the path need to be opened or closed? Does it need to be oriented in a special way?

Also I found that I can rotate the cross section on its plane, but I cannot rotate the plane itself in 3D (with either extrusion method). The rotation is in # of degrees CW or CCW, but within the same plane. Am I doing it wrong?

Thank you again!