>Do you ever see a need where you would actually want those particular edges in the drawing?

Usually not, maybe on a rare occasion where they help describe a curved surface for reference.

I just didn't want say eliminate them in case others have a need for them.

BTW- Starting with Illustrator CS5 you can use the Line Width Tool to control width and taper.
Also Astute Graphics WidthScribe plug-in can be very handy for people who want to do finessing
of line widths in Illustrator.