One other question:
I need to go back and get 25 Man Portal Jockey achievement in ICC.
How many competent level 100 healers do I realistically need to get that done?
One completely incompetent 100 healer can do it. Source: me, I've never healed at all, I specced holy on my paladin and it heals her in like two heals. If you don't manage it before the portal pops, just take a portal and reset it and try again. Or just wait until 110 when you can probably do it with a bandage.