built-in isight camera on early 2008 macbook air 1,1 Does the (camera + internal microphone) system use a single internal 2.0 USB interface that connects to logic board?

This seems to be the case according to Wikipedia, and ifixit, even though I cant get 100% sure. Also, is LVDS cable involved here?

Edit: looking at ifixit pictures, from step 19 it seems the internal microphone cable is connected to logic board, while all other input from display (ie. also the USB part from isight) goes through display data cable in step 23
The camera, Bluetooth module, keyboard and trackpad all connect internally via USB. No LVDS cable is required or used by the camera. The internal microphone is connected directly to the audio controller.

Take a look at About This Mac from the Apple menu, go to More Info > System Report, and look at the devices listed in the USB category to see the various device connections.