@Michael
I cant wait for environements maps !! look at http://auxpecker.blogspot.com/ its for Rhino and its OH MY GOD (free) awesome for viewing freeform with T-splines. And you can still model while having the environement maps. Maybe speak to auxpecker coder because he has very very good environement maps pictures that he use in Auxpecker. That would save you some time rendering environements maps.
When I say fake reflections, its just an environement map, not object reflecting another object, that's raytracing and today its too heavy to deal with in real time.

> Well, when things combine only one of the edges is kept in the final result,
> the style of the final one will be whichever one was the surviving edge.

My bad, I mean how does MoI display two lines in two different styles (blue and red for example) when they are at the same place in space?
Same for colored solids.