1) It says overclocked, does that mean its already overclocked and when i use it it will over clock?
2) Do I need to overclock it myself, because I don't want it to overclock by itself?
3) Will it still run games on ultra (tomb raider, Hitman, GTA iv) if I don't overclock it?
4) When any card has OC next to it, does that mean you can overclock it, or does that mean it already is?
I dont really know much about overclocking and I dont want to overclock my GPU. My computer will also have an Intel Core i5 3330 and Corsair Vengeance 8GB, will this be enough to run games all full settings?
It also comes with two games which you can sell and thus get it less than the 660.
If you badly want the 660, the OC means its factory overclocked, in most cases the GPU is binned from a lot and the better OCing ones go in them. It will clock up to the overclock, yes, keep in mind the voltage is normally not pushed up, so basically no damage will be done to the card.
You'll run games pretty well, keep in mind GTA IV is a horribly optimized game, so don't really expect it to run it on ultra. Tomb Raider and hitman you'll see pretty good framerates, but not necessarily run it at ultra, I'm not too sure about that.