Could trying to disable WindowsServer.plist break my iMac it will no longer start?
This is a bit of a mess - but you could do one test to isolate the hardware from the software (and some of the hardware).

Power off the Mac and pull the power cord. Disconnect everything you can - keyboard, mouse, etc... Take out all RAM - the manuals are at http://support.apple.com/manuals if you are not familiar with the safety precautions and tools needed.

Then plug in only the power cord and wait a few seconds. If the Mac doesn't start up, press the power button once.


You should get three beeps if the machine is healthy.
Power it off and put the RAM back in - be sure it's seated well / pushed in completely.
Connect only the mouse and power it on holding the mouse button down (button one if there are several).
The CD should come out if the hardware is healthy.
Shut it down (you can use the mouse or connect a keyboard if needed).
Now power on with the shift key held.


At this point, if your Mac booted, it's likely everything is fine and you can use Apple's support to troubleshoot the startup issue. If anything doesn't go like I mentioned - you should take a printout of this and what your results were and post here, or seek hardware help.