1992 red 244 200K miles, AT, purchased from the 2nd owner for a grand (he bought it from the 1st owner at 100K in 1996, 4 years of very hard driving)

Good tires, 2 year old exhaust system all the way to exhaust manifold, shocks and suspension feel normal, no rust on the body or underneath, minor damage to the right side of the chunk frame ($500 body work in the future), good black cloth interior

After I drove it home (20 miles of highway. I did make sure there is plenty oil and coolant before the drive), I noticed the following problems. When you start the car cold (after it stopped idling for a while), I can hear that the RPM is low (probably under or around 500), I have to slightly step on the gas pedal to get it going. I’m positive that after I cleaned the TB and all the other components and a set of new cables and plugs, this will be fixed. However, the problem puzzles me the most (or scares) is the following:

Symptom: After initial start, if I step on the gas hard (not really too hard) there is a scary high pitch squeaking that sounds exactly like a car trying to stop at 60 mph (brake squeaking). It only does it when I try to rev up the rpm from low point (500 or lower?). If I don’t step on the gas hard and just open the TB gently and get the engine running smoothly (once it warms up, it idles well). From this point, no matter how hard I step on the gas, it does not make the scary noise anymore.

Things already tried or will try:

1. no belt from crank to AC compressor and PS pump, still does the same
2. Will try to take off the belt to the water pump and alternator and try
This is to try to eliminate the possibility that it’s a belt noise.

My worst fear:
1. Broken bearings in the engine (crank or cam?). If so, should it make noise all the time instead of what I described? I hope that this is NOT true.
2. What else?