I don't have a '95 so maybe someone'll correct me on some details...

The thermostat doesn't turn the fan on. The fan switch is that sensor in the thermostat housing. It's NOT the same as the other one near the upper radiator hose. That one's for the ECU. The smaller one is for the dashboard gauge. They don't 'share' information...

Does the temperature stay OK when you're driving? Your engine makes way more heat driving than it does when idling. The reason it gets hot idling is because there's no air moving thru the radiator. If your thermostat were stuck closed, then it would overheat worse while driving.