That could actually make for an intriguing story line...
This time, you are not chasing a missing identity, but your missing courage that you lost somewhere ? B)
would make for an interesting game, but playing through a whole game as a coward, then npcs calling you a coward and stuff
Thats why you might turn to the dark side ?
but then, what if your playing a light side game?
If it was easy being "good", there would probably be less "bad" guys in the univers.
Why should the light siders always have the easy/obvious path through the game ?
It could be a challenge, having to play through a game, where people are mocking you (spitting in your general direction), abusing your, challenging your ancestry etc. and you know you have to keep you head cool (no emotions, etc.). As a reward, you get a date with either the "white haired" chick or some manly idol (depending on your gender) in the end.
If you fall to the dark side and give in to anger and retribution, you get sheer destructive power and the right to gloat over the ashes of your enemies. But forget about any friendships, never turn your back on anybody, and no eye candy in the end.
Could be possible in a game, where you started out losing your courage at some time, and are now struggling to build it up again. Having courage is not in itself a DS/LS thing, both good and bad guys can have it or not. It's how you lost it and how you regain it, that decides your "path" through the game.
Just my imagination spinning slightly out of control.