So how does your engine actually aquire KR?

Do stock supercharged cars naturally have it? Or does just changing the pulley small give it to you?

I have a stock 2002 SSEI and i have a 180* T-stat and ZZP 1.0 PCM.

How much knock retard would i have around because i never have scanned for it?

Good question. KR is still one of those things I havent quite wrapped my head around, but there are a lot of good threads here on the forum devoted exclusively to that. To my knowledge a car doest't have any KR stock and fresh from the floor. Its like you said only when more boost is added i.e. a pully swap, that is if you get to small of a pully, that your in danger of aquiring the dreaded KR and the potential to chip a piston head. For 2000+ bonnies I believe you can go as small as a 3.5" pully and be relatively safe, but its always good to do some supporting mods, (upgraded exhaust, intake, etc.) Just so your car performs better and handles the extra boost better as well.

KR is derived by the PCM when it reads the noise on the knock channels from the two sensors. The amount of noise is monitored and when it reaches specified amounts the pcm retards timing. This retardation is known as knock retard or the retarding of the timing to stop predetonation/knock

Working on what bill said. If you are modding your car you know the 4 cycles of your engine. on the power stoke for optimum power the spark plug lights up a few degrees before top dead center of the compression stroke. When you engine is knocking the gas being compressed ignites before the safe ignition zone of compression stroke. So to combate this the PCM electrically retards the spark. so the spark ignites farther into the compression stroke. This keeps your engine in one piece but you do loose power. Simple things can be done by you to stop predetination. You a higher grade gas. If you are boosted should be using 93 anyways. ON the 2000+ the 3.8 sometimes get carbon deposits which cause hot spots to start predetination. A head gasket but on wrong can cause an over hang in the cylinder causing a hot spot.
In short owning a boosted car turbo or blown you will always be fighting KR Check on ZZP'* tech articles some good stuff there.