#1
where are some other positions of the "box" other than the one at the 8th, 9th, and 10th frets?

Im just asking because someone told me about it last night and its pretty fun to mess around with.
#3
You could start by moving what you know to different keys.
I think this is what you mean by the Albert King Box:

/-----------8-10
/----8-10-----
/-9-----------
/-------------
/-------------
/-------------
look at the note on the 10th fret of the B string. that's the root note, A. Pay extra special attention to it, because it will be your anchor point as you move around the neck or you want to jump into the box from other positions. If you want to play in a different key, all you have to do is scoot that shape up and down the fretboard.
Here are a few examples:

in E in G in D
/----------3--5---------------6--8----------------------13--15------------
/----3-5----------------6-8-------------------13--15----------------------
/-4-------------------7-------------------12--------------------------------
/------------------------------------------------------------------------------
/------------------------------------------------------------------------------
/------------------------------------------------------------------------------

So yeah, if you know your notes on the B string you should be able to make pretty fine use of the Albert King box. Hope that helps.