Flaming array or wave of flame?

I did a run a while back where I was using the belt that gives you more fire damage and the sigil that enhances the barrier. I was running around with only around 140HP I think. I also was a Knight-Enchanter and was pretty much always in the middle of the enemy mobs. In that situation Flaming Array is really, really amazing, especially if you've got high critical chance/critical damage. So if you plan on being in the center of it all, I'd go with the Flaming Array. Will keep up your barrier nicely, deal a lot of damage and does a bit of control when the enemies are knocked down.

The Wave of Flame is better if you'd like to keep enemies away from you or direct them somewhere, but in my experience it doesn't deal that much damage, which is something to consider if you want to go with the Knight-Enchanter specialization to keep up your barrier. I played with pretty much only offensive spells aside from Fade Cloak and had a very consistent barrier up all the time.

I'm not sure about the damage bug. I was playing on nightmare difficulty, so I was getting zero damage on some enemies anyways due to resistances. Chaotic Focus definitely worked. When I was landing critical hits towards endgame I did around 40k damage on some enemies if I remember correctly. Without it I had around 14k to 20k hits, I think.

But Chaotic Focus should work pretty well with Knight-Enchanter, since more damage equals more barrier, so there shouldn't be too much of a difference.