Your defenses are more then fine, you could get away with a lot less when farming act3 mp0. You're using 4pc Zuni but have no real damage dealing ability that you can spam to actually need the regen. Zombie bears would be much more suitable instead of Locust Swarm afaik. I'd drop Zuni's ring and helm, get some more crit/critdmg on those 2 pieces. Also your bracers seem kind of low on crit chance. And if you have the cash, go for a Manajuma's with a socket.