It sounds like you've been with this problem(s) for quite a while without fixing it. For running hot with the ac on, and at a stop, I'd make sure the auxillary fan is kicking on. Also make sure the fan clutch isn't just freewheeling when the temp gets hot, it should pull air as it gets hotter. You need these to pull air across the radiator when stopped. Having he ac on adds heat to the cooling system. When you drive down the road, the ram air does the job of cooling the radiator and condensor, but when stopped, you need the fans to work.
I'm sure you've checked the coolant level. To make sure your water pump is flowing, run the engine with the radiator cap off (cool engine), rev the engine by hand or have someone do it for you, and you should see a stream of coolant come out of the bleeder hole. Those cars came with plastic impellars on the water pump, and they will eventually strip off the shaft and either fail completely, or slip on the shaft as the revs go up-but still pump some at idle, or slow speed.
An engine that runs too cool is usually a thermostat.