Jamal, I would like to thank you for this great write-up! My wife's keyboard got drenched in hot chocolate to the effect that even after cleaning, the macbook didn't switch on anymore and the left shift key was constantly triggered. Turned out that some hot chocolate had seeped between the two plastic layers and shortened out some connections. Got a new keyboard for £28 and fitted it in a couple of hours. All working again now.
The one thing that nearly got me was the connector for the keyboard cable. I managed to pull it off the circuit board, but succeded in soldering it back on with a tiny 12V soldering iron. Turns out you have to lift the plastic tab opposite the cable till it stands up at right angles to the board. Then the cable slides out easily.
Thanks again, Andreas
PS: After three days of tinkering, I am now able to completely dismantle and re-assemble a unibody macbook in under half an hour.