I am a Rogue with a -4 Strength modifier. For those attacks that add strength on damage, this is highly inconvenient. Currently, one of my natural attacks deals 1d2-4 damage. Since Sneak attack is added to this, the 5d6 from that source generally gets it to a useful point.
However, the problem is critical hits. My best case damage for a non-critical hit is (30+2-4=) 28, while my best case damage for a critical hit is (30+2+2-4-4=) 26. The math works similarly for any other roll as well.
This is because Sneak Attack damage is not multiplied on critical hits. However, it is added to the hit damage, therefore the minimum 1 nonlethal damage never kicks in, and the high penalty for strength reduces my damage.
It seems counter-intuitive that a critical hit deals less damage than a non-critical hit. Am I allowed to choose not to multiply my damage?
The critical hit section of the combat page does not note the possibility, but it is possible they did not consider this edge-case.
I want to get all the relevant rules before I ask the GM to make a ruling.