Im pretty sure healing in Cyrodill nets healers XP
It should also outside of there IMO
Just tagging every mob once as a healer could become tediously repetitive so I do have apathy towards the issue of this thread.
However the heals I was fortunate to group with did dps as well as heal and I lean towards favoring heals that throw out some attks.
I watched health meters as well and don't remember multiple low health party members being an issue but that doesn't mean it isn't an issue somewhere.
I would suggest one of the following added to your rotation
if sorcerer class your pet that attks
shield that does "x" damage while providing "y" protection to all party (fighter guild has one) and it is stamina resourced
siphons does "x" damage with "y%" healing all party
etc.
some Ultimates also do healing+damage but ultimates are not always up
So one aoe spell or shield or summons as your opener but don't start the fight first, let your tank or whoever cc /stealth start the fights healer