1)
Trolling also includes dishonesty as a requirement. Posting something you honestly stand behind, but know could (or will) piss people off, isn't trolling. Warping your opinions and personality specifically to piss people off (or just confuse / show them up; single rhetorical bait questions not included; jabs and quips that are supposed to be understood as such, are neither; Socratic irony comes close) is trolling.
There's another word for the former thing: insult.
Added for Aspies.
And Alzies.