Seeing as you just want to validate your script, I would suggest doing it like this:

Code:
alias checkscripts {
  var %i = 1 
  while ($script(%i) != $null) {
    if (!$istok(%scripts,$nopath($script(%i)),32)) { 
      .signal scriptload $script(%i)
      %scripts = $addtok(%scripts,$nopath($script(%i)),32)
    }
    inc %i
  }
}
on *:start:{ 
  var %i = 1
  while ($script(%i) != $null) {
    %scripts = $addtok(%scripts,$nopath($v1),32)
    inc %i
  }
  .timer 0 60 checkscripts
}
on *:signal:scriptload:{
  ; Validate script ($1-) here.
  if ($script_not_valid) { 
    ; Use $input() to warn the user that the script may conflict with existing loaded scripts and offer them the chance to unload it. 
  }
}