If your shooting an opponent with the normal range of the weapon that would be D1 difficultywith Clear Shot, does that mean the difficulty lowers to D0?
In my opininon no. The normal difficulty does not change. If the target is closer or further away then the difficulty lowers one level.
So if your weapon has medium range as standard you can shoot for close, medium and long ranges for diff. 1.
The Talent states:
He reduces the penalty for firing at a range other than the weapon’s optimal range by one step, to a minimum of zero.
That means, only the PENALTY gets reduced, not the Difficulty, and not the penalty for other reasons other than firing at shorter or longer range than the weapon’s optimal range.