Does smoking affect retina or the vitreous (back part) of the eye in anyway other than in macular degeneration?

You are correct. Smoking is always a bad thing and is best avoided. The only known problem related to smoking in the back of the eye is the macular area, but we always advise smokers to stop immediately because so many body functions are affected and it is a leading cause of death.
Yes. Yes, there is some evidence that smoking can be associated with macular degeneration changes for sure.
There is little. Proof that smoking alone affects the retina or vitreous, other than making macular degeneration worse or causing optic nerve problems (rare). Smoking does promote cataract progression, and is generally very unhealthy and should be avoided!