1) you should not need the driver disk. Just plug the monitor in and turn on.
2)Yes, you can use 2 monitors if you swap connections.
3) you can use the DVI lead but you will not notice any difference. You can use either supplied lead but not both at the same time.
4) You can change he settings after the monitor is on. personally I don't think that there will be much difference but there may be some if you are a mad gamer.
5)You ca alter the contrast etc by your graphic card options or by using the buttons on the front of the monitor.