i am very paranoid about Blizzard "banning" me for automating too much (there is anecdotal/apocryphal evidence that they monitor specifically for activity not associated with a physical keyboard/mouse action, and label it "botting").
basically, i run two copies of the game at the same time on the same system, all in window mode. i put one character on follow, and play the other. i manually "switch screens" as needed (for buffing, healing, chain pulling, looting, etc).
the only addon for this that i use currently is
Hydra. about the only things i allow it to do that might otherwise need an explicit input action is jumping on a mount, and auto-accepting escort quests.