Given that the control script is a bit beyond you, the question is really moot.
HOWEVER, I will say that if you added
if ( %response == 0 ) { respond(~keywordlesstopic) } at some appropriate moment in the control script, then it would call such a topic (if such a topic existed).
Providing a non developer with the instructions to put it into an “appropriate moment” is a bit risky, but I think I figured it out. Thanks that gave me a chance to learn more
Even deactivated the quibble part, while I was at it.
Got now a ~generaltopic, which makes for me kind of intuitive sense.
The order is now: First ~introduction, then ~generaltopic and later if I need specific topics.
I hope once I am finished I can provide back some example files for others to use for a simple informational type of bot.