You can replace
Code:
  else { 
    mode $2 +b $mask($address($3,2),2)
    .kick $2-3 $iif($4 == $null,$read(txt\insult.txt),$4-)
  }

with
Code:
  else { 
    .ban -k $2 $address($3,2) $iif(!$4,$read(txt\insult.txt),$4-)
  }