Visiting car forums is an easy way to become paranoid about stuff.
Remember that mainly only problems are discussed on forums (and the internet in general). The vast majority that don't have problems never say their [whatever] is working fine. Why would you?
If you want to change parts as 'preventative maintenance', or 'just in case' where does it end? Maybe everyone should change their water pumps every week "just in case"?
I am guilty of succombing to the paranoia regarding water pumps. I changed the thermostat and coolant on my M54 a while ago and now wish I had changed the water pump aswell because the forums told me it was essential. Every time I drive the car now my eyes are glued to the coolant temperature gauge and I now believe I have a 'ticking time bomb'. I probably haven't!