The A/C compressor failed, requiring replacement. System has worked 100% since.
The power steering box required a pitman arm seal replacement.
The water pump bearing exhibited more wear/wobble than I have ever seen, requiring a water pump replacement - however, it never leaked any coolant.
The radiator upper tank deteriorated badly enough to require a replacement radiator.
The internal regulator/alternator failed intermittently and repeatedly, requiring replacement.
The headliner sagged and required total replacement.
The tailgate window rear switch failed and required replacement.
The front leather seats cracked and split.
Both front window "flex racks" failed, requiring replacement.
Both front door speakers deteriorated and required replacement.
The fuel tank skid plate has rusted out at the attaching bolts.
The lower rear quarters and rockers have rusted.
The 360 V-8 is exhibiting a bottom end noise.
The fuel sending unit ground connection failed, indicating false fuel level.
The power door locks have failed to operate properly.
The front passenger inner door handle broke completely off.
While this Jeep Grand Wagoneer came equipped with all the luxury features anyone could require in the late 80's SUV market, poor quality and high repair expenses detract from ownership.
You will find with any 20 year old, four wheel drive vehicle, things like on your rig will need to be replaced. No matter who made them. I bought mine and expected to replace or repair pretty much the list that you created. It is a given.
It happens with a 20 plus year old truck. Yes AMC did use bad sheet metal and steel. I've got an 88 that I use as a off road buggy, and it sat for a year and has got 168000 miles, and it only needs some tweaks here and there.