I'm curious - I've taken my ibook apart and replaced hardware that had broken, I have TONS of screws... Can anyone direct me to a diagram, etc. that will inform me of ESSENTIAL screws, if those even exist.
All screws are essential to the structure and function of the unit. Missing or improperly placed screws can short out the system and cause malfunction. I would advise you to search for your ibook on the ifixit take apart guide and try and place as many screws back as possible. They provide you with size of each screw and color code where they are supposed to go its pretty simple.