If you're having problems with your teammates over-commiting to passing lanes, try bumping down "Play Passing Lanes" to 80 (for the USER, of course). As for Duncan getting tired, I would NOT recommend lowering the fatigue rate. In some games (pre-patch), fatigue just seems to take over and have too strong of an effect. However, this is rare so I wouldn't worry about it. If this is a continuous, repeating problem, though, you can try lowering Fatigue Rate or increasing Stamina by 2-3.
Anyways, I too have noticed the lack of attention toward PC users by the slider community, so I'm glad I could fill that void a little!