I think Ghostbreed is asking if you use out-of-game knowledge on later playthroughs that your game character is not supposed to know without finding the information within the game. This is common with all games that do not feature random passwords, keycodes and riddles. I have yet to finish System Shock but I imagine that I will play it like any other game with this "problem": Roleplay it like I am that character, or more simply put: act like I don't know and have my character rediscover the information. No opening doors until my character has learned what I already know from an earlier playthrough.
I'm not much for min-maxing stats in games either. I can not go into a singleplayer game with an end-game spec in mind because it is not why I get into the adventure in the first place. Most gamers are of the opinion that developing character builds is what cRPGs are all about, but I'm always in it for the adventure, to act out a plausible character. I don't hit as hard and I don't get all the rewards, but I was there when it happened man, I was there.