I consider the dip the upper body squat.
Every muscle is working, including the lats and friends.
So with that in mind I would consider using this exercise as a focus rather than an after thought or an adjunct to another exercise...dips one day, bench stuff on another.
The lean forward or backward is moot when you have considerable kg tied around the waist as you reallly don't have an option, just get yourself in the strongest position and dip heavy weight to make use of this great exercise.
If you are interested in developing your triceps, pushdowns on a cable are far safer.
A favorite of mine is to dip to fatigue and then without any rest AT ALL run to and exercise like dumbbell flys or something similar to this movement, this really fatigues the pecs, as the triceps will always fatigue before the larger pectoral muscles.
Try it.