yes
No.
No, but you can use the Guitar Hero guitar in Rock Band. This is a link to a chart for a good idea of what guitar to get. http://www.gamespot.com/features/6183555/index.html
Yes it is compatible \X...X/
Assuming that your Guitar Hero guitar is a PlayStation 2 version and not Xbox or Wii, then yes it is compatible with Rock Band for PS2.
The Guitar Hero 3 guitar is not compatible with Rock Band on the Wii. And the Rock Band guitar is not compatible with Guitar Hero 3. You can try anyways but I'm pretty sure they don't work.
Yes. The Guitar is compatible with both guitar hero 2 and 3. Also, the guitar hero guitar on xbox 360 is compatible with rock band for xbox 360.
All Guitar Hero Instrument are compatible with Band Hero.
No it will not.
Yes, they are compatible
No, Rock Band 1 was released way before Guitar Hero World Tour so the drums aren't compatible. Also the guitar hero world tour drums have cymbals and the rock band doesn't. In the end: You can't back track.
Yes the guitar hero guitars are completely compatible with rock band.
yes but why would you play Rock Band if you have Guitar Hero Metallica?