yes as long its the same console
Yes!
Yes
yes
probably not...
No, you can't use controllers between different consoles, but only with the same console. So you can use Guitar Hero PS2 controllers with Rock Band PS2, but not Wii.
Rock Band games on PS2 only support PS2-style guitars and PS2/3 Rock Band guitars and drum kits. Guitar Hero: Aerosmith and newer on PS2 support all instruments from all consoles that the games have note charts for (so no drums on GH:Aerosmith but 360 and PS3 drums work on all full-band GH games).
you can use it for the bass, guitar, and drums, just not the microphone
you can use the ps2 one's
If Guitar Hero World Tour is on PS2 then yes. If it is for a different game system then no.
the guitar hero or the rock band 2 microphone.
If you have a GH3 Wireless Les Paul guitar with a USB connection then, YES
No cause the guitar hero 5 drums have 5 buttons and the rock band drums have 4 buttons