hi
if ($nick isop $chan || $nick ishop $chan) {
can be
if $nick(#,$nick,oh) {

msg $chan $iif(!$2,Syntax is !kb nick time-in-minutes reason <== you forgot a parenthesis

so i think that have to be

msg # $iif(!$2,Syntax is !kb nick time-in-minutes reason,nick must be on #)

better to put $iif($4, Reason for ban: $4-) in the msg afer kick

you have to add an antiflood

on *:text:!kb *:#:{
  if !%wfld {
    set -u2 %wfld 1
    if $nick(#,$nick,oh) {
      if (!$2) || ($2 !ison #) {
      ...
    ...