I keep going over and over the posts, trying to see if I missed something. Makes me think of things like bad gas, the simple solutions. But in the end it seems to be something PCM controlled. Since we haven't gotten any codes, we have just going down the line of possible things that would make PCM change. The cat. converter was just keep in mind. I would leave that for a last resort.
I would have to say that your manual isn't very good. I have one that bears the same name as my socks and underwear that has alot of useful info. on checking these sensors and such. I am not one to just replace parts, unless its a common fault. I just hate to see someone spend $ on things that aren't needed. I understand your feeling on the replacement of parts, but then you start thinking when enough is enough. Yeah, I am trying to get you to invest in a better manual. Enough of that though.
As we said that it sounds like PCM is changing to make vehicle run bad. A bad PCM will usually throw a code though, or at least a "check engine light". Since we don't have codes, we are just going through process of elimination. Because its intermittant, it seems to be one of the sensors since we eliminated fuel pressure.
TPS sounds as if it was good, although the age of it was in question so replaced. MAP replaced. o2 sensor needs checked. IAT/ACT sensor needs checked, its usually between manifold and fuel rail behind distributor. I can't remember all sensors for that year. You might check for a crankshaft postion sensor. Keep EGR controls in mind. I can't see why it would be a problem at idle unless its creating a vacuum leak. Check all wires and connections to sensors and to PCM. Including the wires to the injectors. When occurring you might check to be sure sensors are still receiving their supply voltages. Maybe even losing voltage to PCM.
As for o2 sensor, I usually just replace them after I make sure it getting supply voltage. If its not getting voltage, its usually not the sensor. Other than that they have a mind of their own. One thing to remember, its best to reset PCM after replacing sensors.
As for the description of the motor dying, it does sound like the computer is telling it to do something it can't. But, because of it being intermittant, the computer can't make up its mind. Now we are back to no codes.
Anyhow, I hope I didn't ramble too much, its been a long day.

Does anyone else have anything too add?

 

Plastic fuel line ? By all means don't crimp it. I'm not familar w/ that. Usually its rubber hose to tank.