Thinking of adding an on/off switch and maybe some flood protection

on $*:text:/!\bopen\b/iS:#:{
  if !$nick(#,$nick,vr) && $group(#bar) = off {
    .enable #bar
    msg # The bar is now open for business!
  }
}
#bar off
on $*:text:/!(\S+)|(close)/S:#:{
  if !%t { 
    inc -u4 %t
    if $regml(1) = close && !$nick(#,$nick,vr) && $group(#bar) = on {
      .disable #bar
      msg # The bar has been closed for the day!
    }
    else { $bartender($regml(1)) }
  }
}
alias -l bartender {

Then at the end of the script, put "#bar end"

 :error | reseterror
}
#bar end

The command will then be !open to open and !close to close the bar. The basic flood protection is 4 seconds between every trigger. The !close and !open command are only reserved for ops and above, not for regular users.