Since you drop a lot of agi, moving you away from the crit cap, you can safely drop some hit rating as well to get a bit of agi back. Putting 10agi+10haste gems in all yellow sockets and moving the nightmare tear to the blue socket in your weapon, and filling the other sockets with 34/20 arpen should do the trick. You can safely put 20 agi enchant on your gloves as well. Lastly, since you're hit and arpen capped, black magic should be the best enchant for you.
With arpen food you should end up at 1395 arpen, 170 hit rating and 144 expertise rating = 1.8% avoided attacks with a crit rating vs lvl83 of 68.4%.