#1
I own an old Korean made Epiphone Les Paul standard. I decided to set up my own guitar so I peaked down the neck and noticed that the high E string was straight and the the low e string side had a bow away from the strings. I adjusted the truss rod, which was completely loose, and got the bow out of the low e string side, but now the treble side had an upward bow causing all types of string buzz. I kept letting off of the truss rod, until there was no more string buzz. Is there any way to correct this?
#3
It sounds like the neck is actually twisted, which is bad, as I don't know if anything can be done to fix it. If it doesn't bother your playing much, then just let it be - if it does, might be that the guitar is done for, as with a guitar like that it's probably too expensive to have a luthier make a new neck and put it on, considering it costs a lot even with bolt-ons, and your guitar is set-neck.
Gear:

Guitars: Ibanez SV5470F, Ibanez Xpt700, Fender MIM Standard Stratocaster ('04-'05), Jackson Ps-2
Ashton AG200,
Amps: ENGL E530, Bugera 6262-212,
FX: TC Electronics G-major 2, Behringer EQ700, Morley Volume / Wah
#4
If its twisted like you say it is, with slightly more relief on the bass side, thats actually not a bad thing (unless its a big difference, like it probably is)
Because of the gauge of the lower strings, ideally the guitar would have a little bit more relief on the bass side, to avoid buzz while keeping the action reasonably low.

Set the truss rod so the treble side is basically straight. You can find a guide on setting the neck relief in the Ultimate Setup Thread stickied in EG.
#5
I just remembered that the strings that I use are light top heavy bottom for drop tunings. I think that this would be most of the reason for this. I set it to the point where it plays its best so I guess that it will have to do.