Hello,
I am having a similar problem (see attached screenshot). I have a model in which some solid objects are coincident with one another. Edges from the solids behind are showing through the relatively thin solid in front. I’m running with a intel 400 graphics card which i know isn’t recommended but everything else runs fine.
The model is fairly large compared to these parts and if I export these smaller parts into a new empty model space the problem disappears. Similarly if I invert-hide everything in the full model except these parts the problem disappears. I’m doing all my modeling in rendered mode. So invert hide solves it but i can’t do that all the time. I’m pulling views into a layout for annotating for a build manual. 
Updated rhino, nothing
Graphics card drivers up to date
Clear draw order… nothing
Playing with anti aliasing… nothing
fiddling with open GL settings… nothing.
Restoring render mode defaults… nothing
The problem exists in shaded mode as well and only presents itself at certain shallow-ish viewing angles.
Any ideas?