I am glad to see this thread started
It is my feeling (and techs please correct me if I am wrong) that if the boot is torn and there has been no leakage of grease then just replace the boot. If the grease has started to leak then you have let the boot run bad for too long. If it is making the clicking noise them replace the 1/2 shaft.
Can 1/2 shafts be rebuilt or is it better just to replace it with a rebuilt unit?
My wifes CRV had a boot come loose and I caught it when the grease had just started to sling out. I just put a hose clamp over the existing loose clamp and let it ride.
My 300D is going to need some attention in this area when I get out of the engine compartment.