At certain zoom levels it get wiggly for me. at others not. On a MBP, Preview. And it changes if I put in on another monitor. I think you see better results on a Retina display, but few people have those--and good printing is important.
Edges are rendered as vector lines in Hybrid so they'll be the same in both Hybrid and Vector. Fog won't fade out vector lines. The lines need to also be rendered in Raster for that to work.
I've now solved the problem, which was due to corrupt preferences. The solution procedure was as follows:
Close SketchUp.
Open a Finder window.
Click Go in the top menu bar, press and hold the Option key, then click Library when it appears in the list.
Click Preferences.
Click and drag the file com.sketchup.sketchup.plist to Trash.
Launch SketchUp.