I'm using the both for a solid and a hollow.
It's a normal way to use. (separate circuits for without interference)
These sound are similar.
Vib-Ch is littel bit trebly for effect the Vibrato and the Revevb.
The difference is about 0.5~1 on the Treble.
Owner's Maual says "the VIBRATO ChANNEL is affected by both the REVERB and VIBRATO features, and also provides more treble boost
than the NOMAL CHANNEL.
Schematic
http://support.fender.com/schematics..._schematic.pdf
Answers ; Sametime plugging is no problem, only the sametime playing is bad sounds by two players