Here's one thought. Are by any chance confusing the ECU by fussing with the throttle while you turn it on or try to start it? If you are playing with the throttle while it is initializing you confuse its TPS calibration and it will not run right. It's only happened to me once or twice when I was in a hurry and tried to rush things but I can see it happening all the time if you didn't know not to do that.
(Actually I think the only time you need to worry about this is when first turning the ignition on, like while the pump is priming.)
Without reviewing what you have already tried and what you haven't, did you check the ignition coil connectors? Slipping fuel pump? (Shouldn't affect 2010 but you never know.) O2 sensor is removed? If none of these things is the issue, I suggest a second opinion at another dealer or get ibeat and figure it out yourself. The first dealer may have screwed things up rather than getting them right.
Also, is the PCV installed yet?
(Actually I think the only time you need to worry about this is when first turning the ignition on, like while the pump is priming.)
Without reviewing what you have already tried and what you haven't, did you check the ignition coil connectors? Slipping fuel pump? (Shouldn't affect 2010 but you never know.) O2 sensor is removed? If none of these things is the issue, I suggest a second opinion at another dealer or get ibeat and figure it out yourself. The first dealer may have screwed things up rather than getting them right.
Also, is the PCV installed yet?