I have a question: When people imagine (or play) this scenario, do they give any consideration to the AI player's portrayal, or do they just take "AI" as blanket permission to say anything they want, no matter how unlikely?

I interpret the rules as allowing for the later, although I do act AI-like.

(I also imagine his scripted list of strategies are strongly designed for the typical LWer and would not work on an "average" person.)

Although I have never played against an average person, I would suspect my winrate against average people would actually be higher. I do have arguments which are LW specific, but I also have many that aren't.