Ah, it's missing a way to get 1/2 sneak attack on undead/other. I recommend adding an Adept ability or just changing sneak attack.
The capstone ability lets the Rogue sneak attack anything once per round, but an ability such as you suggest might make a good Master ability.
Master ability. Piercing Strike (Ex): When the rogue makes a sneak attack against a creature that is immune to her sneak attack damage, she instead deals half of her sneak attack damage to the creature.
Last edited by Chambers; 2010-07-23 at 03:11 PM.
"We have sent many to Hell, to smooth our way," said I, "and we are standing yet and holding blades. What more?"