Frankly, there would be much CPU power needed for that. Starting a timer isn't something you can even notice, being the mere human that one is. and since it's not starting a new one, but restarting an existing one, you won't get your RAM clogged up with timers either.
As for the $away: the moment you hit the ENTER key, your $away is reset. So it's normal that mIRC then displays the value 0.
