#1
ive looked it up and havent had any luck so what do u do is there a certain fret u can go by like standard (5th fret) and drop d (7th fret) i dont kno so plz help me tune to drop a
#3
7th string's 7th fret should match the 6th string

unless you want ultra limp strings then 12th fret on the E should match the A
Warning: The above post may contain lethal levels of radiation, sharp objects and sexiness.
Proceed with extreme caution!
#4
First of all, that's 3.5 steps down plus the bottom string 4.5 steps down. You're going to need at least 11 guage guitar strings. If you have them already, then you can buy a guitar tuner (they're not expensive) and tune the strings from starting from the fattest A, E, A, D, F#, B. The fattest string should sound like the third fattest string, only a little lower (it will be an octave below).
Bari Build

_\_\ll/_/_
__\ _ /__
___ \/ ___