Can we expect a presence of the church via NPCs and/or a story arch?

Die hard paladin fan here, and with the most prominent story element in the Diablo universe being heaven and hell, I wouldn't feel very immersed if the church and their warriors weren't a strong element. Representing the good of humanity, I'd sortof expect to see this type of character somewhere of importance.

Unless the paladins and their church were of the first casualties in D3. I'd have to cry if that were the case..

In the same vein of holy men, would the monk be able to not only wield armor and weapons, but be able to use them to any effect? Priest with a strong arm is priest with a strong arm right?

The Knights of Westmarch and cult of Rathma still exist, so the chances of coming across a paladin and/or necromancer through your travels are pretty good.