Yes, you can use a mouse and a keyboard as long as they are usb or bluetooth. For usb you can just plug and play, for bluetooth you'll have to pair them before you can use them.
u cant unless the mouse and keyboard is usb
Playstation 3 do not use CDs for games but can play other CDs
No, you can't use ps2 controllers to play ps3.
Use the handle.
You can not play PlayStation 3 games on a PlayStation 1, but you can play PlayStation 1 games on a PlayStation 3. All of the PlayStation consoles are backwards compatible.