IAC will usually not cause any problems except at idle. The car will usually die at idle because there isn't the right amount of bypass air for the engine to continue running. Off idle and under load the car will run just as if the IAC was fine.

TPS will be dependent on throttle position. The TPS is basically a potentiometer so, the resistance value it sends back to the ecu varies. The contacts inside the TPS will eventually wear out, but it usually happens in the partial throttle range since that's where the throttle is for most street driving.