Act 1 u need 0 resistance or hp. Ive had just 30k hp, tho around 20k dps unbuffed which jumped up to 80k with wotb along with 40-50% to crit.
Takes 5-10 seconds to kill champs and ignore pain gives you enough time to survive.
Act 2 is different story, had to swap few items and most of the stuff for defensive, mainly all res and look for high armor, you still need some str tho otherwise you'll never kill the mobs and ull die anyways as u cant tank them forever.
Only just managed to kill maghda, cant tank that even with full defensive, had to swap for weapon throw build and kite her for 10min lol.
I think you will need 500+ resistances along with 13k armor before you can survive in act 2 -_-, best to just group with some good dps that can get things down quickly.