why dont you try putting everything to standard first before asking questions.
your ecu wont have a clue what to do without everything plugged in.
once you've done that replace the cheap bits first such as the water tempt sensor which can make running rough. a sticky idle controle valve sorted my idling issue but DONT buy a pattern part. either get a Bosche part from another golf or fork out for a new one the pattern parts are beyond sh!t.