Wow that is some hard targetting specially if you are camping close to many non-aggro mob or another party, and worst if you are in an alliance. Here is the proper and easy way to macro as WHM:
Ctrl + 1
/p <CURE> ===> <p0>
/ma "Cure" <p0>
/wait 5
/p MP: <mp> <mpp>
....
Ctrl + 6
/p <CURE> ===> <p5>
/ma "Cure" <p5>
/wait 5
/p MP: <mp> <mpp>
<p0> is You from the Party List on the bottom right corner of your screen
<p1> is the Member Below You from the Party List
<p2> is the Member Below <p1>
...so on
By using <pX>, you don't need to target party member to heal them.
I have Ctrl+1 - Ctrl+6 set to "Cure" and Alt+1 - Alt+6 set to "Cure II".
Ctrl+7 = Silence
Ctrl+8 = Dia
Ctrl+9 = Protectra
Ctrl+0 = Protect <t> (used usually on puller if not around for Protectra)
Alt+7 = /item "Apple Pie" <me> (or any pie you can afford)
Alt+8 = /item "Orange Juice" <me> (or any juice you can afford)
Alt+9 = /item "Hi Ether" <me> (just in case of emergency)
Alt+0 = /ma "Benediction" <me> (just in case things gets ugly)
I have this setup in my Macro Set #4, so I just switch to it whenever I'm in a party.