What is the life time of a shaft/club..

Essentially yes, things will give way... but its not going to happen before you/we get board of the kit or it looks too shabby.

Iron grooves are important as they help move debris away from the club face but you would have to work very very very hard to kill an iron groove.

Iron shafts will lose there spring but again, only once years and years old and very well worked.

So essentially yes, but no not really.