How to properly setup a dual trussrod (6 string) Please Help

Just curious on several things, I do know how to setup a bass but had some questions..

A.) do the individual rods affect the other? like does the treble sides adjustment affect the bass sides

B.) Is it the same as adjusting any other trussrod like a single

C.) My G and C string seem to not have the volume of the BEAD strings its like a volume drop off but seems like a small boost in the mid knob brings them right up to par. But could this have something to do with the trussrod questions above.

Thanks a ton,
Brett