I did have a former "life" as a guitarist many years ago - doing mostly Cream covers, but suffered the problem of being self-taught. I found that I reached a stage where I could not improve - having fundamentally "learned it wrong" from the start, so it all fell away.
Then a motorcycle accident smashed the fourth finger top knuckle of my left hand about 10 years ago - which makes any attempts at soloing, pitiful. Even chords ain't as easy as they were

So I largely leave it alone - and try to "finger-style" and flat-pick on the Fusion, when required . . . .
Never got close to a guitar-synth, but I do remember way back - didn't Casio produce a "Midi Guitar"? Looked like an SG if I remember?
Two sets of strings. One for the pick and one for fretting . . . . both sets disappeared into the body under the finger guard between the PUPS?
Or am I wrong?
No matter. I think your findings/observations, using the Fusion as a guitarsynth will certainly add a new dimension in here . . .
There are some quite interesting guitar programs in the presets, as well as a raft of ARP guitar-strums too.
I look forward to hear what you think/find . . . .
Best Regards
parametric