It's not all that complicated. This should be easy to diagnose. The accessories with worn bearing do not make a rattling noise. The water pump will make a tinkly kind of sound. The alternator makes sort of a growling sounds as will the idle and tensioner pulleys. It's obviously not the power steering pump. I'm quite familiar with a noisy compressor. All one has to do is turn on the AC and listen for it. There's no need to disconnect anything. I'm assuming that he has checked everything else but the pump.
You know, I don't want to be argumentative, but you seem to be ignoring all the good advice you got so far. It's just not that complicated. Get a stethoscope, use a piece of heater hose, or vacuum line, and listen for the noise. And what is the noise on startup? A loud squealing noise? If so, the belt is slipping. It's either too loose, or there's an unusual load on it. If the belt is too loose, it's either the wrong belt, or the tensioner is bad. In fact, tensioners have marks on them with a pointer that needs to fall between the marks when the belt is installed. Did you look for that?
If you get a loud squealing on acceleration, it's possible the AC head pressure is going too high, which would usually indicate a bad coolant fan.
Regardless of all this, didn't you say the alternator feels rough? Do you have any idea how common it is for those bearings to fail? This is what you need the stethoscope for - they're like 5 bucks or something. If the alternator is bad, it's going to be really obvious.
Why are you talking about replacing steering pumps, compressors, clutch bearings, when all those seem to be the least likely problem areas?
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