Basically, raise your agility, it is much to low for a SV hunter. Also your AP needs a serious buff.
Replace your gloves, shoes and shoulders as soon as possible.
Change most of your gems to the +agi gems (ignore the socket bonus on most of your items, they are not worth it).
Put AP enchants on your bracers and gloves (after you have found a new pair).
Your talent build is a cookie cutter SV build thus you are doing ok there.
Thus gear up, replace greens with blues and eventually blues with epics. Look out for agility and keep in mind that you'll still need some AP to hurt with your shots. And keep in mind that enchants can really boost your damage output so enchant your gear if it is somewhat decent (especially bracers and gloves as those are rather cheap enchants).
Crit will increase with more agility, so don't focus on that.