#1
well im using this to help me learn the major scale http://www.zentao.com/guitar/theory/major-scale.html

And well heres the diagram for the fretboard for the C major scale



The 2 notes ive circled, fret 15 and 17 on the D string.... They're F and G so shouldnt they be part of the major scale and the sites just accidently missed them? or is there something i dont know here?

Oh, and am i right in thinking that you just shift notes one fret across for the next semitone?
#3
(I cant see your picture so i looked at the website and im assuming your talking about the "combining the two" diagram) The reason why it isnt marked is because its transposed on to the B string.