Funny how you first started your claims with "midway to late Act 1" when you won't be higher than level 8 at the end of Act 1.
It's pretty clear that you either don't play the game, don't read what is actually being written before spitting out hypotheticals, or you don't even actually believe your own words.
Finally, even if this hypothetical and wholly unreliable and unrealistic sequence works, you have zero left in the tank to do anything for many turns after. This is your proof that everything is fine, and that elemental casters are comparable, if not superior?
OK.
Do us all a favor and go play the game to see that this doesn't work in a non Lone Wolf build. Lone Wolf seems to be the panacea logic behind X build being fine around here, while simultaneously dismissing what other builds can do with it as well. Lone Wolf may as well be an easy mode buff.
I'll just begin by saying that this isn't a lonewolf build, and if it was the damage numbers would be a lot higher than that. It appears you really don't know your damage ranges, or really understand AP values. So we'll move on.
Let's address your actual criticism since you're unable to extrapolate basic numbers to match scale to see if my statements are correct, and if they're wrong where the missing values are. So, we'll go with the more conceptual ones.
The main concern is what use is a mage after they've expended all their cool downs? For now, let's disregard moving the goal posts from 'is it even possible' to 'what happens afterwards'. Honestly, the only thing that you can do from there on out is use consumables and attack.
That seems pretty discouraging right? The only way to make this worth it is if every elementalist nabs 1-2 targets either in CC or kills. This also means there will be an upper limit to what you can do in certain situations, and in others you will have to rely on luck to proc certain effects like shocked into stun. However, most situations you'll not really run into that issue; the first mage will expend most of his or her cool downs but the rest of the party should be relatively full in the tank.
When you do face that upper limit and beyond, it's when you resort to using Source powered spells and abilities. Be it chain lightning, or simply Time Warp to use AP to re-position your enemies so that your spells can hit more than 1-2 targets.
Your melee attacks with a staff isn't that far off from a 2H either, but because of how itemization it can be pretty hard to reach parity and more often than not you're behind by 15-20% damage which, depending on your game plan, might be questionable.
