I understand the concern of getting stuck in the middle of no-place, and it can cost you time and $$$ if it happens. There is an issue with the plastic radiator necks becoming brittle and failing. I have not done anything with mine, but I understand that there is a metal sleeve available to reenforce it. I've looked at mine and it seems OK, but I am careful not to over-tighten the clamps. I assume I will just end up replacing mine when it no longer cools adequately.

My wheel bearings end up getting repacked only when the brake rotors are replaced. I did have a rear wheel bearing seize and ruin the hub a few months ago, but it didn't get me stuck. I do bring my car to a good indy mechanic for most significant work and he does a good job of looking for any problems.