dont care about mana, with voodoo + rain dance rune (mana regen) and passive VQ, u can have unlimited mana anyway

for killing boss it's enough, u cant survive 10 sec anyway
and with enough dps, boss probably die within 10 sec

Sounds like you need more armour and resists and life on hit. With the stats below, I can take Butcher's charge or the pull and smash or the fiery floor. Basically just sit next to him and kill him (very slowly, though).

My current build: (I keep changing things up from time to time)
36k hp
450++ resists
5.1k armor
1.3k hp regen
1250 life on hit
7k dps
38 mana/sec

CC effects:
8% chill, 7% freeze, 2% stun, 3.3% slow

Passives:
Bad Medicine, Jungle Fortitude, Blood Ritual

Spells:
Firebomb - Firepit
Spirit Walk - Healing Journey
Acid Cloud - Acid Rain
Corpse Spider - Spider Queen
Horrify - Frightening Aspect
Zombie Charger - Zombie Bears

Working quite well for me at this moment. Able to solo Act 2 past Maghda. Tried Vision Quest builds, didn't like it. With this build, I kind of like the balance it offers. Pretty tanky, have 2 oh sh!t skills, 1 low mana AoE/CC proc/damage reduction/life gain in Spider Queen. And Zombie Bears can be use for certain situations that calls for burst damage.

Against most elites, even Molten/Plague, I can sit and tank. With 3 skills constantly providing AoE life on hits. So far, only freeze bomb and fire chain elites are really bothersome.

Definitely need more dps, but at least I don't die that much.