The only decent stuff I've found thus far is some WoWhead guides. As a general rule I don't usually use WoWHead for my strategy guides as I seem to have issues navigating their site (uses up so many of my CPU resources). But here is a link to the overall guide, it has the first 5 bosses done already.
http://www.wowhead.com/guides/emeral...9-demon-hunter
They seem pretty detailed.
Second Question
This is the way I see it currently with my experience being that I've run quite a few mythics as either a DPS (Enhance) or Resto and I'll be running the raids for my guild so I've been trying to play with a diverse set of groups in order to figure out comps.
Holy Pallies are close range healers now, in the sense that they heal targets near them very, very well. I think that their niche as a tank healer is still very valid. Raid healing is really not their thing. I like to think of the paladin as a healer who tries to mitigate what he can. Between the Judgment ability that heals allies who attack the pally's target as well as Aura of Mercy which heals allies near you. It's a bit like Healing Stream Totem, except you are mobile and able to sit near the people who need the heals. I think the best way to describe them is as a
Proximity Healer. Allies near them are going to stay pretty healthy, but they aren't great at healing lots of people from a distance.