tepponogu, as for your clicking problem. Odds are that is a CV shaft. If you are wondering what that is, if you look under the front bumper of your truck and look at the inside part of your front wheels, you will see a black rubber ribbed boot coming from the center of the wheel running to the center of the truck. This is the CV axle. What you can do is pull the truck into a dirt or gravel lot and put the truck into 4HI. Now, do some decent accelerations and do some with the wheel turned too. Don't need to be doing anything crazy, but some decent things. if the noise really starts to get loud, then that pretty much confirms the CV axle. Otherwise, you have have an old problem that was to be fixed via a TSB that added some springs to the front differential. There was known to be a little bit of slop up there and you would get a single "Thud" when taking off. It was more of an issue with the 99-02 trucks, but some earlier trucks showed it too.
As for things being dangerous in the suspension, it is not any more dangerous than any other vehicle. You maintain the truck, you have nothing to fear. You ignore it, then stand by to stand by. The only "catastrophic failure" that I can think of is the wheel studs. But, if they haven't failed by now, they aren't. This was part of the reason why the newer trucks are 6 lug wheels and the 99-02's went to 14mm studs.
As for the groans, like was mentioned, the ball joints and tie rod ends are notorious for making noise. Look and see if you have grease fittings on these items. From the factory, there were none, but if the parts have been replaced, most aftermarket ones have a fitting. Try applying a little bit of grease to those items with the grease fittings and see what happens.
