It would be great if you could prioritize a heroes skills, so if you were running a build intended to keep a certain skill up, It would easier. Also maybe more choices than the 3 aggressive, guard, and avoid combat.
You can already assign hotkeys for hero skills. It sounds like you want Anet to make you a cheap bot program so you can use your heroes without micro managing them. Either learn to use builds they can use without microing, or learn how to micro.
Just put all the hero bars up in window mode, and mirco it yourself. More mind input for your heroes makes you more skilled and is more fun to play. Bots never can beet the human brain. Just go and improve your apm.
To make it a usefull system it should be quite complicated.
Microing is a skill, learn it.
I agree how easy it is to micro depends on you build.
a frontline war is harder then a spirit spammer.