Farming/Gearing Questions

Hey all. A few questions:

1: Post campaign and once you've out-levelled the "zones" of Cruel Act 3, is there nowhere I can go to safely farm?
*I assumed once I completed a map, I'd be able to go back and do it again just to farm. Sure, no additional map progress but that's fine if I just want to farm. Looks like I cannot do this. Am I just really missing something here? Using up a way stone and risking map loss is the only way to farm?

2: If you complete a map but stick around to keep farming and you die, do you lose the map even though it was completed?

3: Is it true you lose experience if you die once you hit level 70? I die from lag fairly often so a tad concerned here.

Thanks!