I just started a game and so far have done the bandit camp, the crypt, and the lizard man cave and In all that time neeshka has only had 1 successful backstab and that was on the wizard in the bandit camp, every other encounter she gets spotted like 10 feet away with a hide and silent movement skill of 17. is my game glitched or are rogues really just that bad?
Backstabs are a 2nd edition D&D thing. You don't need to use stealth anymore, and in fact stealth is pretty useless in the OC.
In 3rd edition backstabbing's been replaced by sneak attacks (NWN 2 is actually based on 3.5 ed but sneak attacks haven't changed), which trigger when a rogue, or any other character with sneak attack dices, attacks someone who's not attacking him.
It can trigger out of stealth, sure, but the most efficient way to use them is to actually wait for the enemies to beat on your tank, then attack the same one as your tank with your rogue. You'll do a lot of bonus damage that way. Just be careful not to let the enemy attack your rogue or not only will you lose your sneak attack bonus damage, your squishy rogue is also likely to die fast.
Sneak attacks can also work with a ranged weapon provided the rogue is very close to the target.
Keep in mind that all enemies that are immune to critical hits are also immune to sneak attacks. This includes all undead, elementals, constructs and a few other things.