Mk1 2000 reg 2.0l esp

My brothers focus keeps shutting off (not stalling) sometimes when pulling away (on clutch but Definatley not stalling)

Also there is a crunch noise when trying to start and can take ages to start ( maybe 1 in 75 starts, hot or cold )

Also a slight knock on idle which goes when clutch depressed and not always there.

It's a petrol on over 100,000 (not far over)

Any ideas ??