Looks nice to me, but maybe you can change the on/off function so you can only see "off" if it's on and "on" if it's off.

So, for example you can change this:

.on: alerts on
.off: alerts off

into this:

.Set $iif(%alert == on, OFF, ON ) :set %alert $iif(%alert == on,off,on) |  echo -a 3nickalert is now turned %alert

Haven't test it yet but you can try, with this you don't even need the alerts alias ;).

Anyway, nice snippet, keep up the good work :)!