I don't think all three is out of the question.
He's certainly got quite the imagination, I'll give him that.
"Just a troll" certainly doesn't cut it. If he's a troll, he's possibly the most diligent and hardworking troll on the internet.
If he's not a troll, he can't be all that intelligent judging by his posts. At least he doesn't think very clearly.
Schizophrenic? Not Scepti. Sandokhan most likely is. Scepti is probably just a bit paranoid, maybe even delusional, but he lacks that sort of otherworldly, bizarrely disjointed thinking that characterizes a real schizophrenic.