Is a cleric's channel energy weaker when energy drained? I.E. A level 3 cleric gets 1 negative level, do they channel for 1d6 or 2d6? Is channel energy dice number a "level dependent variable"?
For each negative level a creature has, it takes a cumulative –1 penalty on all ability checks, attack rolls, combat maneuver checks, Combat Maneuver Defense, saving throws, and skill checks. In addition, the creature reduces its current and total hit points by 5 for each negative level it possesses. The creature is also treated as one level lower for the purpose of level-dependent variables (such as spellcasting) for each negative level possessed.
From the bolded area, I am inclined to say that channel energy would become weaker because the strength of it is level dependent.