Mouseover macro for support spells :
#showtooltip
/cast [target=mouseover,help][help][target=player] Chain Heal
So let's say you have an ennemy targeted. If you mouse hover a friend frame in your ui and press the keybind for this macro you'll use the support spell on him.
If you don t hover anyone you'll use it on your target if it's friendly.
And if your target is an ennemy it will heal you.
Works with any support spells like paly shields and hands, priests bubbles etc etc. By using it you just don t need to click a target to use a support spell anymore as long as you have them in your raid/party ui.
EDIT: I think there s a minor glyph who reduces the hearthstone casting for pallies.