I will first admit i am not a expert on macros.

Now that is out of the way i have noticed two commands that stuck out to me in particular

They are:
/targetenemyplayer
/targetfriendplayer

Again since i do not know much of macors these are all blind guesses on their usage.

/targetenemyplayer
/cast shadowstep
/reset=1 (needed?)
/cast cheapshot

And with you shammy types out there

/targetfriendplayer
/cast chain heal

And last but not least is there a way that you can use /targetenemyplayer to locate a raid marking, for example
/targetenemyplayer "skull"

Is there a way to target skull in general through any macro

last but not least.. am i dreaming and drifting?