Balance Druids do considerably more damage on the move than lighting bolt through their DoTs, including Lunar Shower, and Starfall. Shooting Star procs roughly equate to Lava Surge Procs so they are the same there.
If you just like that playstyle of short casts while moving, Fire Mage, Hunter, and Warlocks all provide it.
Also, coming from a fury warrior, you don't want a strong execute. You get balanced around it, which means that you end up with significantly weaker >20% health damage. Fights where I don't get significant execute time, the most glaring example of which for me in ToT is Megaera, I am almost embarrased by my damage.