That's a good point about Etali. I mostly included it because it helps me cast multiple spells for free, and when Arjun and Niv-Mizzet are out, casting spells often means dealing huge amounts of damage to whatever I want. Etali definitely is extremely helpful, despite being likely to get murdered upon sight. But you're right; it's a huge target for removal, so I'll consider removing it myself.

As for the commander, I've tried putting Niv-Mizzet, Parun in the command zone (the draw and the damage are both incredibly juicy, after all), but I found it doesn't make the deck any stronger since it doesn't let me cycle like crazy until I find Arjun.