#1
For some reason my G string goes out of tune really easily - they are fairly old so could that be the problem?

I dont think there is a problem with the gutar or machine heads as it is a Gibson Les Paul Custom with Grover tuners
Gear:

Gibson Les Paul Custom (Ebony)
Bodenhamer modded Maxon OD808
Marshall DSL 401 Combo
Mesa/Boogie F-50 w/ Marshall TSL 2x12 cab
#3
yes
Gear:

Gibson Les Paul Custom (Ebony)
Bodenhamer modded Maxon OD808
Marshall DSL 401 Combo
Mesa/Boogie F-50 w/ Marshall TSL 2x12 cab
#4
I have no idea then lol.....do u bend a lot on that string or anything like that??Maybe it is the old strings...Not sure.