Chaos/Fire multiplayer Warlock - Second Rite or Hellfire?

I’m running my first character with my BF through Elite right now and I was making a Warlock. The BF is playing an Elementalist who uses Fire Strike, Jacks, and Grenado.

http://grimcalc.com/build/1b3LXdF -> http://grimcalc.com/build/ZNgeo2u
Without current gear : +385% Fire, +179% Chaos
With current gear : +886% Fire, +539% Chaos
Both measured with buffs on.

Here’s my current > rougly planned skill distribution, I was assuming some +skill gear (of which I have a modest handful right now). I dont have legendaries and everything planned out, I’m just playing organically at the moment and equipping stuff that’s good as I find it.

I was considering max Second Rite for the chaos boost, but then I noticed that Hellhound has Hellfire. Since my BF and I both do fire damage it makes sense to use that aura, except I have no devotions / gear to benefit pets. Hellhound has a listed 9k HP pool at 1 skill point which is far more than me, but I assume pets suffer the same difficulty penalty to resistances as players do. So the question : Will a 1 skill pt Hellhound just get squished on Elite / Ultimate even when set to defensive, or will the hellhound be survivable enough to be worth it for the Hellfire aura’s fire + chaos boost?

I’m sure some people will want to complain that it’s not an optimal build, that I should change this or that around for one reason or another, that my constellations are bad, etc. That’s not what I am asking advice for here. I dont know how much +skill or +chaos% gear I will end up with, and I likely wont end up farming this character to optimization because the BF doesn’t want to play the same game over again 3 times. I may not even get to level 85.

At the moment it would benefit chaos more than fire damage for sure, and while my fire damage is already high I am playing in multiplayer so the increased damage is passed on to my BF’s Elementalist as well. The real issue is that if the Hellhound dies too easily to be useful I can’t unspend my mastery points in Occultist. If the aura isn’t worth it for damage, then Second Rite surely isn’t either.