#1
I feel kind of dumb asking this, but I've never had a guitar set up that required any modification.

So, I want to get a guitar(Esp/Ltd EC-1000) set up for drop A# with 56-13 guage strings. I know that this will require some amount of modification to the nut and bridge to accomadate the larger strings.

My question is, if I had this set up done, would it affect playability if I wanted to go back to E standard(with normal guage strings of course), granted that I had another set up done?
#3
I like all different tunings.

I think every tuning has a distinct tone that I like over others.

A# and Eb are my two favorites.