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.
Show a video of this working. Seriously. You write in such a way that makes it look like you're faking having more knowledge on the actual mechanics than you actually do, and you keep dancing around giving real answers to the questions asked, or claims made.
I will gladly eat a bucket of crow if proven wrong, but I've spent enough time with the game to know that the things you keep suggesting simply do not work; or at least they don't work during the periods you're claiming that they do. It's like you're a data analyst telling a field agent how to do their job, because the manual and spreadsheets tell you how it
should work, not how it actually does in real time.
Your whole "I could show you, but then I'd have to kill you" spiel doesn't really cut it.
Regarding Elemental Arrows: they scale with the school of the matching element. Problem is, they don't scale with INT and scale decently using FIN instead. Similarly with the various arrows that are non physical (poison cloud/shock arrow etc). So using a bow with an elemental caster won't really do anything for you over simply using a wand, other than for physical use only. You'd still be better off simply using Bouncing Shield instead, even with the two turn cooldown.
