Ah gotya,

That is the knock sensor and the ecu uses this to listen for detonation.

The vvt works on oil presure. The valve on top of the valve cover is the solenoid that lets the oil into the vvt pulley. The ecu knows where the cam timing is by the cam phase sensor.

I havnt done the belt yet but it looks like its the same as any zetec except you have to hold the vvt pulley with a spanner.

The oil cooler is as much an oil warmer as anything elts. Its designed to get the engine up to tempreture quicker to reduce emissions on warm up.

Having spoken to a few people, most arnt bothering with the extra plumbing. As there are lots of zetec's out there over 200bhp with out one.