My IAC is bad and in order to keep my car running while a stop sign/light is to have one foot on the brake and one foot on the gas.
Is this an effective fix to travel until I get it fixed?
Should I just not drive it?
This wont do any damage to your engine until you have an accident making a mistake with the pedals:) The IAC would only doing the same function that you are doing manually. I do think you have more of a problem than the IAC being faulty, since it should just add extra air when you switch things on like the lights, air con etc. Maybe your throttle butterfly valve is dirty and not allowing sufficient air through for normal idle speed.
As HandyHowie said, this won't cause any damage.
However, there is a better way, based on the assumption that you have a foot on the brake because you leave the car in D at the lights. If the car will still idle in N with a bad IAC, select N as you're coming to a stop and put it back in D as you press the gas pedal to set off again. Make sure the revs are up a bit before selecting D. You'll also save fuel this way.