What's my worst piece of gear; i.e. what should I look to replace? Hopefully for under 1million. With this build I can trash MP0, and do MP1 (can do runs without dying, usually die a few times depending on the elite abilities). I haven't tried MP2.
Chest, Helm, and pants to me. Your belt has res all and plus life so it's a good EHP starter belt.
Helm - If you want dps and don't care about EHP you can pick up a socketed andariel's and get 8/9IAS and 4.5 crit with 160int. Should be a good dps upgrade. OR if you want sustainability, go with a socketed Storm Crow. You'll get LOH and APOC which won't do a ton since you're using disentigrate so it doesnt work with APOC very well but it will give you something.
Chest- Look for an item like this: 100 int / 100 vit / res all 65+ / 2 or 3 sockets. You'll gain some massive EHP that way. you'll lose some dps, but it'll be a heavy survivability upgrade.
Legs - Pretty much the same: 100 int / 100 vit / res all 65+ / 1 or 2 sockets. Same case as you'll lose a little int for a lot of survivability.
What most people do at lower level before they can get tal rasha's and zuni's and all the great legendaries is go for ehp on Chest, Belt, Pants, and boots. Then rock DPS on all the other stats. (Wrists go both ways cause you can get a good pair of strongarm bracers for cheap). So aim for high EHP in those slots, and dps in the others.
Then once you get more gold you can work on getting some dps into those slots by getting like a Tal Rasha's Chest, or a 150 int chest /legs, etc.
You could get the socketed andariels to offset the damage loss from gaining more EHP from chest / pants.
I updated my pants and actually increased life, dps, and armor/resistance....
Hmm monster power 2 is doable. Ill say I died on 33% of the elite encounters, so probably not that efficient. However, tactially, I could just get to 5 NV and then only actively look for mobs, skipping difficult elites. might make sense for the xp boost.