We would only use 'like' if an incomplete sentence followed 'like.' We would use 'as,' 'as if,' or 'as though' if a complete sentence followed. Are these correct, then? He acted like a buffoon. He acted as a buffoon would. And if a sentence ends with 'then,' does a comma go before it? If she goes to the event, I'm not going, then. Thanks.
1. I'd say both are correct. 2. You've already implied the 'then' with the 'if', so I'd leave it out.
