u posted on wrong section dude.. try hardcore mode section.
most regulars here(same with barb forum, dh forum etc) don't play the noob mode(hardcore mode), therefore can't give u much tips.
1. ehp > dps in hardcore mode cos u only get one chance.
(i.e. my sc wiz = 427k dps / 281k ehp, but my hc dh = 126k dps / 2.44m ehp)
2. dc related death(lag, pc hang/crash) is the no1 cause for death amongst exp players with decent gear.
i.e. dc death in hc is inevitable, so get high ehp/hp regen, n use high ehp/dps enchantress+maximus, etc. (check my hc toon, I even used enchantress ehp calculator cos shes my backup protection against dc, http://us.battle.net/d3/en/forum/topic/6794832543)
3. high LS, LoH or high dps won't help u at all when u dc. so use skills like blur, galvanizing ward etc.