I just added to Tidy_Trax's code, to include the delete request date as you speced,
and a ON START, in case the bot shut down, it well sweep the file for any to remove or any to setup timers for to remove.


Code:
alias addnick { write delete_nicks.txt $1 $asctime(dd.mm.yyyy H:nn) }
alias remnick { write -dw" $+ $1 *" delete_nicks.txt }
;
on *:text:!delete_me:#:{
  addnick $nick
  .timer 1 604800 remnick $nick
}
;
on *:start:{
  var %i = $lines(delete_nicks.txt)
  while (%i) {
    var %line = $read(delete_nicks.txt,nt,%i)
    var %nick = $gettok(%line,1,32)
    var %ctime = $calc($ctime($gettok(%line,2-,32)) + 604800
    if (%ctime <= $ctime) { remnick %nick }
    else { .timer 1 $calc(%ctime - $ctime) remnick %nick }
    dec %i
  }
}