You would only consider changing the clutch if you find that the fly is faulty.
A worn clutch would not give you the issue that you have.
The crank position sensor picks up timing from the flywheel and the CPS is fitted to the outside of the engine/gearbox.
This is the hydraulic tensioner that you will see through the inspection plate, and you are looking for how much the plunger is protruding from the hydraulic housing, or if the large slider/guide is damaged
This is the main chain, however there are another 2 shorter chains at the top of the engine which drives the cam shafts.
I would also be looking at the VVT solenoids or the split ring seals on both the front timing cover plate stubby shafts.
Your issue could be numerous things and quite a bit of diagnostics may be required by a certified tech who knows his way around a 350Z to get an informed diagnoses.
I would also consider getting the car hooked up to Consult and read the ECU live data and check the cam position at idle.
Even low engine oil resulting in low oil pressure can throw these codes.