You probably want to replace your belt and amulet. Look for high resistances and most importantly, high life. As a dual striker you'll be in for some dangerous shit, so you need to be able to survive big hits.

You want to cap your elemental resists at 75% each. I just glanced over your items, but they didn't exactly seem to increase resistances sufficiently. Your rings too will eventually need an upgrade. The cold damage doesn't really do anything for you, phys damage however will scale beautifully with your crit.

Generally speaking, you don't actually want to wear too many uniques, as they often don't give you a healthy balance of life and resists. I'm not so sure about Atziri's steps either to be honest.

Oh, and one Bino alone is fine. Get a better dagger instead on the offhand. Right now you're fairly squishy, but the Bino's will help you stay alive.

I assume you've taken the assassin ascendancy? If not you probably should. It'll make it laughably easy to give you the maximum amount of 95% critchance, which will allow you to get more defensive items without losing damage potential.

PS: You probably want to replace Herald of Thunder with Herald of ash, it'll benefit you more. I also suggest linking Fortify to your whirling blades instead of assassins mark, I'd put that elsewhere.

Oh, and if you're holding off your fifth gem in your chest (I suggest Faster Attacks) due to mana reasons, you should try skilling into Mana Drinker, to the right of the shadow starting area. It doesn't seem like much, but makes quite a difference.

Talking of your skilltree, if you ever need more life, at the bottom of the duelist cluster are three nice nodes.

Have fun!