My main problem with just keywords is that one word is a bit vague. I had other RPG's where due to the keywords I accidentally chosen an answer that I didn't want and thus offended an NPC or took the violent way out of a quest instead of the peaceful answer.
I'm not saying you should put down all the text you are going to say for all choices, but 1 sentence or something out of the entire response should clarify it better then 1 word. Except for maybe options that return more often, like "leave".
