That's what I did. I have the Insert, Home, Page Up, Delete, End, and Page Down keys bound to target specific henchmen. Of course I usually then have to custom name them. That way I can quickly target and heal a henchman. Healing team members is still a PITA though.
"The danger is not that a particular class is unfit to govern. Every class is unfit to govern." Lord Acton
Madam Enigma's History
I did exactly what you suggested OP. My heal key is 7, and the target arsonist is CTRL-7, making healing him pretty easy. Those keys get a lot of use.
Bah-- let me get back to you on this. I might have a macro for you... What do you have so far that allows for you to target your Arsonist? I just got into creating Macros for my friend's MM.
EDIT:
Here is a macro that would probably work best for you, and be sure to use the Arsonist's new name if you have changed it. In order for it to fire reliably, click the button or hit the hot key twice. Make sure there are no extra spaces anywhere, especially at the end.
/macro Heal "pet_select_name Arsonist$$powexec_name Alkaloid"
/bind [key] "pet_select_name Arsonist$$powexec_name Alkaloid"
Anyway to create a /macro for Alkaloid that points to the arsonist only? I played around with it a bit and couldn't figure it out.
Edit:
Just thought of something , I can create a /macro that targets the arsonist then mash the alkaloid key after I guess