So long as you keep up with proper coolant maintenance, the pump shouldn't wear to the point where it's ineffective. Unfortunately, there's no way to know whether the pump is degraded internally without having some major outward indication, such as insufficient cooling.
As ForesterBill said, check for leakage at the first coolant change and each follow-on change. Leakage from the weep hole indicates a bearing/seal issue, so if you see indications of dried coolant or an active leak, it's time to replace the water pump.
The timing chain should be lifetime, but, as we all know, nothing is lifetime. If you start to hear a rattle or any other noises that can't be located, take it to your mechanic and ensure it's not the timing chain, guides, etc. The chain can stretch over time and the guides can wear.
I think the key to keeping any vehicle long-term, is to be proactive about investigating potential problems, which includes periodically inspecting the vehicle yourself or having a mechanic do this for you.