Coasting engine off in a manual should be done in neutral, not clutch in. The clutch is designed as a momentary break between the engine and trans to allow gear shifting, not as a means of coasting.
Coasting in an automatic should be done in neutral, engine running as the transmission pump is driven off the input shaft, not the output shaft. Running the auto with the engine off means no tranny fluid is being pumped around, which means the output shaft is not being lubed, which will burn out bearings and pump crap through the rest of the system when the engine is started again.
If a Saturn overheats when idling, even if coasting at speed, then the water pump isn't pumping enough fluid through the engine. Either that or the thermostat isn't opening all the way.
Hope this helps...
A Saturn automatic will not be harmed by coasting with the engine off. Some Honda automatics can be towed as well. This is why you see so many Saturns being towed behind RV's that are being transferred from the manufacturer to thier dealers.
As mentioned above, if the Saturn overheats, check that the thermostat is opening properly or that the belt is gripping enough. A slipping belt can be the belt worn out or the belt tensioner getting weak. I found this out last year on my Saturn when I kept getting the low battery charge/overheat light with a brand new belt and the temp gauge was in the normal range.
Horsepower is how hard you hit the wall, torque is how much of the wall you take with you.