I found this https://sites.google.com/site/ffxivcontrollerguide/ helpful for determining my controller layout when I heal. The biggest takeaway for me was use of /chotbar copy for my pet hotbar, so I could press L2+R2 or R2+L2 and get to my fairy's actions, & the use of /chotbar change # for Cleric Stance. I settled on this Cleric Stance macro

/micon "Cleric Stance"
/ac "Cleric Stance"
/chotbar change 3
/target <f>
/echo <se.6>DPS MODE

and

/micon "Cleric Stance"
/ac "Cleric Stance"
/chotbar change 1
/target <f>
/echo <se.9>HEALING STANCE
/target <tt>

This macro targets my focus target (a boss) when I go into Cleric Stance & brings up my 3rd hotbar, which has my DPS skills. The other macro brings back the 1st hotbar, which has healing skills, and targets the target of my focus target, which should be the tank. When there's no focus target, it targets the target of the current target, which should also be the tank, but sometimes you'll target an enemy.