Haha, I'm pretty sure that, of Sunic's 4600 posts, at least half contain "Hi Welcome" (excluding his sig).
Heh. The trick to Sunic is to stop thinking of it as a person.
Back in the early days of Battle.net, it was convenient for Diablo players to have a reference for the stats of any item in the game. So someone wrote an IRC chatbot, programmed it with all known stats, and set it loose in Battle.net IRC to answer with them when asked.
He called it "DainBramage". It was incredibly useful, but you wouldn't want to try to have a conversation with it.
Sunic is like that. Ask it a D&D mechanics question, you'll get good and detailed info. Converse with it about anything else, you'll get nonsense. It really doesn't matter whether it is a basement dweller, Asperger's syndrome sufferer, obsessive hobbyist, some kind of bizarre and cunning troll or parody, or an attempt at passing a Turing test. Speculating about its motives is fruitless and kind of uninteresting.
Just use it to learn about obscure feats and spells you may have overlooked. The insults are kind of background static, so constant in both density and character that they can be filtered out with little or no mental effort, and thus don't really affect the signal to noise ratio much.