It's actually pretty helpful to take a gun along at all times. At the end of the level, if nothing is hounding your ass, just start taking apart everything that comes into sight for the matter. Eyes are especially useful - they can drop hover mods, visual enhancers, scanners, and scan interpreters. Stock up on spare parts if you can afford it, power cores, you name it. Then just leave the instant you see a threat (e.g. Programmers).
Edit: Oh, and thanks for the flattery, haha. You did good son. Non-combat is definitely the easiest way to get to -1.