#2
Yeah but not 4 much

If u start on the first fret its F minor Pentatonic Scale and u start on the Thrid fret its G minor Pentatonic Scale ect (I belive idk i totaly taught myself this)
#3
I'm still quite new at this but from what I'm understanding so far, the starting note just tells you which key you are in, so it's up to you.