99 radiator fan problem, engine kill

#1 - I recently noticed some clunking noises from under the hood sometimes when I'm driving. (Surprise, I let my wife - THE car jinx - drive it last week.) I opened the hood and noticed that the radiator fan wasn't running true - about 5 degrees or more off of vertical I'd say. Then after a few seconds and a few clunks, it was back to more or less true vertical. The AC wasn't running, just in case someone is wondering if the clutch is the source of the clunks. What can I do to diagnose this?

#2 - When my wife was driving it last week, the engine killed either before or during a turn and possibly with some clunking. She started it again, and drove off. Since it's only happened once (and only while THE car jinx was driving), I probably can't do much with it. Some posts point me to the PCM which is what exactly and located where? Any suggestions on how to diagnose this one?

#3 - Along with all of this, I've noticed some pinging on acceleration that wasn't there two weeks ago.

#4 - The power steering fluid needs changing (groaning). I've heard of a simple method of emptying the reservoir and putting in new, then repeating after cycling the new in. Is this a good alternative to paying the shop?

Ok, stupid me for asking. I was doing some further checking this weekend, and #1 is obviously the water pump. I don't know why it wasn't so obvious on my initial quick check. One new pump, and it's working like a champ again. It must have a MTBF of 100k miles because I'm at 98k. What else drops out at 100k?

If you still have the chance (if it were me) I would dump the mechanical fan for a couple of slimline electric fans with shrouds. The fan clutch/fan on mine makes a unecessarily high amount of noise, I read that you can reclaim up to 45hp with the electric ones too.