1, front is for FPR back is for standard boost gauge
2, for that big f**k off thing thats under the standard plenum.. to tired to think of its name
3, water return that runs around the back of the head (there is also one running to the front) make sure you replace that bloody piece of hose with a nice new quaility silicon item.. they are an absolute bitch to change while in the car.
4, i cant remember i'll have a look sometime tomorow
5, get a picture of it.. i have a feeling your talking about the water feed tho
also little bit more info on wat your tryin to setup could help possibly