You can add code into your add.pts alias to check if %online.off == 1
Code:
alias add.pts {
  ; dont add points if %online.off == 1
  if %online.off == 1 { return }
  ...
}

or you can mass turn off timer
Code:
on $*:text:/^!online (on|off)/:#uminokaiju:{
  if ($nick != rapidhaste) && ($nick != glummerz) { return }
  if $2 == off {
    set -e %online.off 1 
    $+(.timerpoints.,#,.,*) off
  ...
}

and to prevent gorran_ triggering !online after you turn !online off, you need to add code to check if %online.off == 1 in this event
Code:
on *:TEXT:!online:#uminokaiju: {
  if ($nick == rapidhaste) || ($nick == uminokaiju) || ($nick == glummerz) || ($nick == gorran_) {
    if %online.off == 1 { return }
  ...
}