As Chongo said its bloody hard to use HIPS in NWN2 and 3.5E in general, you may as well find a wall, restealth and go back in... its about the same either way.
As for rogues and HIPS, I doesnt happen. Only shadowdancers, assassins and rangers get it in 3.5e rules (Not sure if the Darkwood stalker PrC gets it as well, pretty sure the ninja base class does though)
The Scout class gets it too, but that is from Complete Adventurer. It's not a prc class either. But this was only a note.
