on $*:text:/^[.!@]topic\b/iS:#: {
  if ($nick isop $chan) && ($nick == $me) {

This will never trigger as you can't trigger your own text event.

My guess is the original code ($me == %Botnick) is usefull if you
wish to chat normally and then when you decide to play bot then
renick to the botnick and let it do it's thing.