Well, not to be negative, but there are bad Crankshaft Position Sensors on the market. It does sound like that is the problem. The RCM fix needs to be done under a magnifying glass to really make the fix. It just isn't visable to the naked eye. One other thing that cause rough idle is the IAT sensor located to the rear driver's side of the engine. They have broking their mounting clips in the past, but the car will run rough and not idle. I would do the easiest first, and try another Crankshaft sensor, then revisit the solder joints. With that said, fuel could do this as well, as a few members have lost their fuel pumps. Good luck....

Ooops, I failed to ask if it were N/A or SRT....if N/A, you won't have an AIT sensor...
And, the code reader woundn't help in this case, none of the above would throw a code. But, having one is a good thing...