To sort out the overboosting problem, just check out the rubber hose that is going to the actuator. Most likely it wil be broken. Just replace it with a piece of hose of the same size.

The knocking and squaking could be the 2 rubber pieces that hold down your font anti-roll bar together with the rods that go from the front anti-roll bar to the dampers of front suspention.

Fitting a new clutch is an easy job, just get a haynes repair manuel and follow the steps. Do fitt a full clutch kit (clutch, clutch cover plate and bearing), because you don't want to this job 3 times just for fun. A standard kit will do if you car is standard.

Belgian Greetz,