Clio rev counter and other faults

Hi, I have just bought a 1996 Clio 1.2RN. It has a few faults, I wonder if anyone can point me in the right direction?

1) Rev counter drops to zero when car is warm. Then the idle speed then goes high

2) Temperature warning light is permanently on (temp. gauge is mid to high)

3) Knocking noise on left hand corners - I think this is the right hand CV joint?

thanks in advance

/Simon