Imo, as a druid you would profit much more from mousover macros or a click addon, because of the many instants we have.
On a class using primarly casting heals you have enough time to pick a target with the mouse and trigger a spell with a keybind, while the prvious heal is still casting.
But I'm also not using any healing addons beside Grid2. I'm targeting with the mouse and casting spells with keybinds.
The way you are describing druids you could also describe a shaman.
Earthild on one target, glyphed riptide on anyone who takes damage...
The "hardest" part back in Cata was to enshure to have the right target for your chain heal. Afaik this part is gone, but I might be wrong here as I hadn't time to play my shamy yet.
The only thing, which might make a druid easier, is the fact that we have lass spells we can use which are usefull. As Norish is currently a complete waste of mana and time, and HT only makes sens with NS.