just asked an enh shaman, said something around 380 from gear is good enough for enh shaman, you will still miss btw, just get enough hit to land most of your attacks, dont try to get cap hit for auto-attack
btw, get more expertise, you need 26 to avoid boss's dodges(thats 6,5%), if you hit the boss from behind he wont parry, so no need to get parry cap expertise
replace exp-hit gems with 20 exp, there is an exp blue back from hc halls of stone or halls of lightning not sure, it can help, if you can, get the back from frost emblems, might help
make sure you got "enough" hit for enh, cap expertise so you wont miss a lot, then boost other stats