The controller featured here is not an official Dualshock 2 controller.

Yes it would. As the the elite is the same HMD but with a different faceplate.

On earlier Xbox 360 S systems, the screws mentioned in step 40 need to be unfastened in order to complete this step

I opened an Xbox 360 S manufactured in 2010. These 5 screws are needed to be undone in order to complete step 30. I didn't know about the one under the sticker so I ended up breaking the housing as a result. I'd appreciate it if you could make a note to step 30 pointing you to this step if you are having trouble taking the side off, as it is highly likely that these screws are the reason.