#1
I want to change the strings on my strat to 8's so my little brother can use it to learn to play without bleeding all over it. I think i have nines on at the moment, so will changing down to 8's mean i have to set the guitar up again?
I didn't think it would, but i'm not an expert tbh.
#2
Not likely, no.
Good music is good music...everything else can go to hell

Gear:
Gibson LP Studio
Fender Blues Deluxe Reissue
Avatar G212H (1xG12H30 1xAlnico Gold)
TS-9 Screamer
Boss Tu-2
Line6 X2-XDS Plus

The Band
#3
you would need to adjust the spring tension a bit, i think that the truss rod and the intonation will stay ok, but you never know.