I have just had a pump failure on my 1.9TDI 2001 Golf, get the water leak investigated asap. if the pump packs up, the cam belt will jam or worse - snap. This happened to mine. if that happens the timing will go out and if your unlucky, the pistons can hit the open valves, bending them and causing about £1k+ worth of damage. If the car is due a cambelt change in the next 10'000 miles soon and its diagnosed as needing a new water pump, then get the garage to change the belt with the pump now. This will save on labour as its all in the same area. I cant comment on the clutch but the idle speed should be easy to sort. Good luck.
Steve, April 2008