Can't post because level not high enough?

[Bixby]

Suggestion:
/ac "Cure" <t>
/ac "Cure" <tt>

Would suit your needs?
It will cure any PC/NPC directly targetted.
If target is enemy, then it'll skip to 2nd line and cure target of target.

Actually, if the target is an enemy, it will self-cast cure and never make it to the second line.

Macros don't do anything different from using the ability directly on the chosen target (<t>, <tt>, <mo>, whatever). And all heal spells self-cast when the chosen target is hostile.

EDIT: Oh, and how to get rid of the annoying error chime and message?

You can turn off errors in the chat log, but not the sound and not the message that shows up in the middle of the screen.