I have a 2000 Ford Taurus Sedan that has a screeching metal on metal sound when switching gears to reverse?

And the sound is there the entire time you are backing up. Does this sound like a transmission issue? Also hearing a rubbing noise in the steering, and it is a little tight, any idea what that could be? Also heater blows, but not real strong and no heat comes out… Does that sound like a difficult and expensive fix? And could the heater or any of the above issues cause my engine light to light up solid continuously? The car runs pretty good aside from these issues.

You need to have your front tires popped off and have the brakes looked at my friend. Sounds like those components are beyond worn and frankly you shouldn't drive the car because it doesn't sound safe to operate until it gets fixed. As for your heater, you could have low engine coolant.