Typically it needs programming at the dealer.
If you replace the cylinder, you can either have it coded for your existing keys (locksmith or dealer only) or have the new key chip coded to your pass key module.
So you're still going to have to visit the dealer.
Can't start the car? Now you're going to need to tow it there.
Typically not being able to remove the key is related to the park lock solenoid, though I have yet to hear of an issue with the 04+ park lock solenoids. Perhaps they don't have them.
Disabled due to throttle control logically wouldn't be related to the ignition cylinder. It would be related to the electronic throttle control unit and the related wiring.
Google: http://www.justanswer.com/pontiac/1w...e-control.html
http://www.justanswer.com/pontiac/24...e-control.html
