All out of Antifreeze/Coolant, how come my engine didn't overheat!?!? Options

[tomazws]

OK, so this morning just out of curiousity I opened up all the caps under the hood and checked their levels. Found out my Coolant tank is completely empty, way below "LOW", so low that there was nothing there. So immediately I went to the cabinate and poured in everything inside that Toyota 50/50 bottle... but there was only like 1qt left.....

Please not that I don't know anything about motors except changing motor oil and refilling gas from gas station
1. Am I screwed? Is my radiator/engine/car/everything screwed?
2. http://www.6gc.net/forums/index.php?showtopic=22922 <-- in this thread someone questioned if radiator is blown. How do I check if my radiator is blown or not?
3. My gauge reads my engine right in the middle of COLD and HOT.... is the sensor bad?
4. http://www.6gc.net/forums/index.php?showtopic=32767 <-- I think I'm leaking. I've seen red drips under my car, so it shouldn't be head gasket correct? How shall I fix the dripping?
5. http://www.6gc.net/forums/index.php?showtopic=31352 <-- I heard the same sound sometimes, is that a sign that I ran out of coolant or a sign that coolant is leaking into my carpet?
6. http://www.6gc.net/forums/index.php?showtopic=27578 <-- Is Toyota 50/50 bad? Should I switch to Prestone or redlines water wetter?
7. http://www.6gc.net/forums/index.php?showtopic=27378 <-- If I switch from Toyota to Prestone, do I have to flush it first?
8. If I mix the red Toyota fluid with green Prestone fluid, would it mix into a different color?
9. lol am I asking too much questioins?