#1
I saw a thread a little while back that said something about learning intervals when learning the major scale. i didnt kno what intervals were at the time tho so i didnt really read into it. now however, i have taken a music theory class and understand intervals and how the Major Scale is constructed. So i was just wondering what your supposed to do when you are learning the major scale that involves intervals because i cant find that thread. basically i really want to understand the theory aspect of the guitar and be able to play by ear so if you could steer me in that direction that would be great.
#2
i think you mean the intervals of the major scale
tone,tone,semitone,tone,tone,tone,semitone
#4
I'm not quite sure what you're asking.

The major scale contains root, major second, major third, perfect fourth, perfect fifth, major sixth, and major seventh. That's all there is to know about it.
Only play what you hear. If you don’t hear anything, don’t play anything.
-Chick Corea