Ford Tempo 1992 - Started with overheating!

Ford, Tempo, 1992, @100,000miles, 4cyclinders. I bought this car after it had been sitting for about 9 months. When I first got it it was hesitating when I put my foot on the gas, I found a transmission fluid leak, so I put more fluid in it and it stopped. Next the mechanic told me I had an oil leak, but it wasn't worth fixing. One day I was driving it and all of a sudden as I making a turn the steering wheel got extremely stiff. Found out I had to replace the belt (there was only one). This was all done in the same day. After that, it started overheating, around the same time I started to noticed green stuff on the ground under the car. Found out it was antifreeze. Someone told me I could just fill the tank with water and pour water into the radiator until it overflowed and that would help. They saidit wouldn't make since to keep putting in antifreeze because it would leak out. So I did that, it helped, but the car would eventually still overheat. One day I noticed the water in the tank and in the other place was frozen. I put more water in there until it filled up and then drove it to work. The thermometer thing went all the way past H really quick, then just dropped back down all of a sudden to C all the way and it was alright. The very next day the water was frozen again. It was still filled to the top, so I could not put any more in it. The thing went all the way past H again, I thought it was going to do like before, but instead the was a loud popping sound then a very large cloud of white smoke that was too through for to see through. When I got out the was antifreeze everywhere. The next day we had to move the and now it is the same as before, ast long as you put the water/antifreeze in it it runs ok, but eventually overheats. I have taken the car to about 3-4 diffrent mechanics that have all given me a different diagnosis. I have since bought a new car, but my mother wants to try to save this one. What do you think is wrong? Also, just an aside. I am curious as to what was happening when all those events took place. Can anyone shed a light on this disaster? P.S. This all took place in the span of about 4 months!