#1
As all of us know, there's pre defined shapes of all positions for different scales (major, minor, pentatonic, diminished etc.). However, what happens when u use (drop c, drop d, drop b) tunings.

I am sure the positions of notes certainly change, and the pre-defined shapes won't work. What one has to do then?
#3
yeah the string that you change will have the pattern change.

an example,

in standard (EADGBE) if you play an Ab, it will be on the 4th fret of the E string.

but if you are in a drop tuneing say (DADGBE) that Ab will now be on the 6th fret.
#4
Dropped tuning allows you to hit a minor 3rd inside your power chords(half-bar or 5th chords)A half step up from where your octave usually is, in standard tuning
e-x A G power chord with a minor 3rd
b-x
g-x
d-8
a-5
d-5
#5
As far a scales go, I only use them for practice. When improvising, I just try not to use the low string and play the pattern the same (as you would in standard) on the rest of the strings.