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Hard starting Pontiac Sunfire

Our daughter has a 1996 Pontiac Sunfire that has recently turned over 100000 miles. It haS A 2.2 with an automatic. Last spring she started to have some minor difficulty with it starting warm. If she would leave it sit,turned off for more than ten minutes and went to restart it it would fire up and stumble and die. She tookit in for a complete tuneup and fule system cleaning and that helped for maybe a little while. ( The fuel filter has been chnaged twice now since the cleaning) So this summer she took it to a different shop and they put his diagnostic computer on it and changed the crankshaft position sensor. Still no good. Took it back and he did some additional cleansing of the fuel intake system (he said whoever did the original cleaning didnt do a thorough job). Still no good so she took it back again and after a week of diddlingwith it replaced the Idle Air Control motor. Still not good. Nowithas gotten to the point of idling rough and even feels like it will stall at a light if she doesnt keep a little pressure on the gas pedal. The last place told her that this is a common problem with GM vehicles and that GM hasnt even figured it out yet. All in all she has invested over $800.00 in this problem and STILL hasnt gotten it remedied. Whats other opinions on the situation?

Does the exhaust smell of gasoline? Does the crankcase/oil smell excessively of gasoline? Any smoke (gray/black) out of the tailpipe?

In short, it sounds like it might be running rich. In the midst of everything everyone has done has anyone checked the fuel pressure / fuel pressure regulator / fuel injectors? Has anyone checked the coolant temperature sensor?

She should take notes, for her mechanic(s), of when the symptoms occur, and under what driving conditions and weather conditions. The more specific and detailed the data collected, the more it will aid the mechanic in diagnosing the problems.
Now, what is the problem? Rough idle? Near stall at idle? How about the start-while-warm problem? Gone? Modified?
Since we can’t do any checks, like cigroller, I suggest checking/changing the engine coolant temperature sensor. Do a fuel pressure leakdown check to see if the fuel injectors are holding fuel pressure after shutting off the engine. Results?