Having not got this far yet, let me ask this. If Auriel is a Dragon God of Time, who is to say what does and does not make sense?
He's not a dragon, remember. But yeah, I think you've got a valid take on it. Auriel can be a cultural Akatosh variant who split off during the Dawn, as the elves (who were then higher on the subgradient chain) experienced him as a champion and one of their own. And he could have departed thereafter, with their Auriel beliefs imprinting on the other Time God variants still extant. And all of this is pre=Convention, and has to make even less sense because of nonlinear time. And you've got Pelinal who was an avatar and a gem, but somehow had a childhood too.
Auri-El, with the hyphen and extra capital, is definitively one of the Akatoshes according to KotN dialog. If sans-hyphen Auriel is the same being then he is Time. So who is to say a being that is itself time is subject to linear cause and effect?
Oh, goodie. Got a quote?
Also, I'm 99% sure that Auri-El=Auriel, just like Pelin-El and Tamri-El.
As for being humanoid enough to wield a bow, well Tsun is both the humanoid we see and the whalebone bridge he guards (assuming Tsun=whale). I guess I'll see soon enough.
Eh, Tsun in Sovgarde was just an avatar. Auriel is never described (prove me wrong, someone!) as a dragon.