#1
What is the most widely used key for this scale? (specifically in metal)

and if possible list a few songs that can help me get used to it, thanks!
-Ibanez SAS36FM
-B.C. Rich Warcock Platinum Edition (my first guitar, noob mistake)
-Roland Cube-30
#5
The most widely used key? Why does it matter? Whatever key your chord progression is in, play the scale in that key.
Someones knowledge of guitar companies spelling determines what amps you can own. Really smart people can own things like Framus because they sound like they might be spelled with a "y" but they aren't.