Will a PPI usually find most problems? clutch/slave cylinder/leaks etc...

 

sure, the obvious ones. pretty hard to tell the condition of a clutch without seeing it unless it slips. absent obvious leaks, the slave is harder also to diagnose, while the failing accumulator pedal stiffness is 96 turbo 101 lol

 

A failing slave can be diagnosed by a leaking front pentosin reservoir and inconsistent clutch catch points. I think you need to drive many cars and get a good idea what these car drive like.