For an guiltless/worriless drive, follow the maintenance schedule.

I've put 165k miles on the original Timing Belt. I swear, every mile since 105k when it was recommended to be replaced, I've been passively concerned with it breaking on me and bending up all kinds of stuff in the multi-valve engine. I now have the parts sitting on my desk at home. But they still won't do any good until they get on the car.

I also just did CV joints. I've seen toooo many cars on the side of the interstate with broken axles. So I made sure I did those within 3 weeks of the "clicking" noise.

Oil needs to be changed regularly. I mean, your engine shouldn't be burning oil, so it's not like there isn't going to be ANY oil in the engine if you don't change at 3000 to 3750 miles. But the quality of the oil does breakdown over time. That's why you wanna keep fresh oil in there. I mean, that's alot of precision metal stuff in the engine rubbing very, very close together. Old broken down oil won't kill the engine immediately, but it will deteriorate the life of the engine in the long run.

Are there any tell tale signs of a dying timing belt? I don't know. I'm starting to think my engine isn't performing at top notch. But then again, your mine also starts telling you crazy stuff too out of guilt/fear.

My honest advice: Do as much of the scheduled maintenance as you can afford. Don't skip a rent/mortgage/car payment for the sake of a timing belt change--it's not THAT serious. But at the same time, don't do like I did--throw away potential servicing dollars on Car Stereo.