the most common thing here with American cars is a tps (throttle positioning sensor) pretty cheap and easy to get to. usually located under the breather/air cleaner. or a vacuum line is disconnected. usually with a vacuum line the car wouldn't start at all without having to pump the gas pedal and continue to do so to keep it running
water in the fuel can cause an idling motor to sputter and/or die.
Idling too low or a bad lock-up torque converter solenoid.
After warm up, my car would die at idle and would decelerate when I pushed the gas pedal hard. I replaced the camshaft sensor and it fixed the problem.
throttle body is not letting enough air in. Idle speed servo, stuck or failed.
because itt needs to be work on
== == You may have a short in the wiring or something is wrong with the computer system in the car.
I sat in my car in the driveway with the car idling, waiting for the kids to come out.
Yes, it could.
You do not provide enough information for a good answer. It depends if it is Fuel Injected or not and other information. Possibly vacuum leak or idle speed too low.
There are various reasons why your car would almost stall when idling. In most cases, this might be an indication of the engine lacking power or capacity due to the failure of the pistons. You should contact a mechanic to diagnose the problem.
The radiator cooling fan is most likely not working.
As long as your car engine is running, it should be OK. An exhausted battery will only become a problem when you try to start the car.