Hi Rogue,
I think the things you said makes sense. But recently there have been more problems. Now my car stops every 10-15 minutes. It does not show overheating problem anymore. It just stops, I let the car sit for couple of hours and it starts again. I took it to Acura dealer for check this time, they first said there was no coolant in radiator (that was because my friend opened up the radiator when it was hot and all liquid flushed out). I told them about it but they were like that was the problem sir. I bring it back from them and the car dies before I reach home. So I take to them again and this time they say it is thermostat, but mind you that my car was not overheating anymore, infact it use to run at normal temperature. But they still changed the thermostat and car still stalls. I think they should have engine error code check facility but I don't know what are they doing.
I agree with you that problem is not mechanical, has nothing to do with heating, might be the previous overheating might have caused some electrical connections around the engine burst out or one of the sensors is bad. I don't know how can they check on the sensors and fix it. I don't want them to replace every sensor one by one and finally that will fix it but that would be lot of money.
The car gives the problem when it is on highway or on local roads, it doesn't matter when I am driving. The 200 rpm problem happens only if I start the car in 15-20 minutes after the car has stalled. If I give it couple of hours and then start then the car starts at 1500 rpm in park and the idle is at 600rpm on drive. Let me know if you need any other information that would help for the suggestions.