I use a click castsequence.
It recasts when the cooldown/duration has expired.
It prioritizes earlier spells over later spells, if both are available.
It casts the last spell (as a fall through), if everything else is on cooldown.

My order is: Flame Shock, Lava Burst, Chain Lightning, Lightning Bolt.
I didn't really see anything in the patch notes to change this.

I would manually cast Flame Nova, when we want AoE.
Have not decided yet on untalenting it or leaving the 2 points there.