Yes
Well, you can buy Guitar Hero Metallica with or without the guitar!
Yes. It is just a Guitar Hero: World Tour guitar controller. However, it is not functional across platforms (i.e. Ps3 controller will not work on a Xbox 360).
Guitar Hero World Tour and Guitar Hero Metallica
Yes
yes but why would you play Rock Band if you have Guitar Hero Metallica?
yes, all of the guitar hero controllers are compatible within the same console. For example any guitar hero controller made for ps2 will work on any guitar hero game on ps2.
i dont no
of course it is
Yes, the controllers can be used for all guitar hero games
Yes
you need a guitar to play ALL guitar hero games.