There's an upper limit on enchantment buffs to bow damage? Aww, and here I was going to one-shot Alduin with a long bow. 
100 enchanting + Grand soul gem + Enchanter's Elixir = +45% damage to [insert weapon skill here], which can be enchanted to up to four item slots, equaling +180%.
Ah. That's pretty damn impressive.
Of course, I do 3x damage per sneak bow attack and currently do 30x per sneak dagger attack. Most things don't survive.
You're right about the poison resist except for those pesky levers. Get it wrong and you get hit with poison dart. I love taking no damage from that.
And you're right about the sneak perk.
I'll have to re-think my armor before I fight Alduin.
But it does look good so maybe I won't...