1. You would of course enchant the weapon with fire or electric damage, but the higher base plus Glacial Spike procs definitely win out with Emberquake.
2. Onslaught is more for the debuff, and dumping the extra points there gives it a good enough duration that you should only need to use it once. Slow is the second best debuff in the game, only slightly behind Blindness.
3. Really? I've heard the opposite every time. Granted it's difficult to tell whether it's even going off once you hit a certain damage threshold.
5. I feel it's too fundamentally flawed. Get hit now so you maybe won't get hit later? Pass.
6. Healbot handles that admirably.
7. This is more a playstyle choice of passive charge building vs another active skill to manage. While it's true that Charge **** doesn't help if the boss has no minions around, that also reduces the efficacy of Dynamo Field. It would require several castings to fill up your charge if you're only hitting the boss with it. In my experience, coming into the boss with a full strength Forcefield and spamming a few Emberquakes tends to drop the boss before it drops your shields.
8. Fire Bash requires a shield, which I guess you could keep on switch if you felt a need, but Emberquake is already so powerful it would only prolong the fight in most cases.
Tremor is alright but most of the damage from an Emberquake build will not be physical, so again I don't feel it's worth the time.
You can watch it happen ingame.
Lightning does 40% weapon damage (not WDPS) as lightning
Thunder does 50-200 lightning damage
Glacial Spike does 225-225 ice damage
This all depends on if OP wants to do things the legit way or if he wants to respec during game, use mods for enchanting etc.
But i tested it in the game and you can take down Punchbag about 10 seconds faster than when using Final Embrace, Mortal Edge, Foe's Collapse or any other 2H weapon (same results are against classic monsters/bosses - tested in Taroch's Tomb). If you have different results, the difference must be in stats allocation or in gems we are using.
Also ember quake would pretty much only be used with quietus right?