I don't think you can use 'if $nick == $me' in an on ACTION event.
This will change all the actions that come from other users, whether that is from a channel or from pm, it will be echoed to the appropriate place:
on ^*:ACTION:*:*: haltdef | echo -lbfrtc action $iif(#,#,$nick) *** $nick $1-
These aliases are replacements for the built-in /me and /describe, so that you can alter the way it looks when you perform an action, again whether that is to a nick or to a channel:
alias me !.me $$1- | echo -tc action $active *** $me $1-
alias describe !.describe $$1- | echo -tc action $1 *** $me $$2-