skeezy,

For Dreamwalker, I just set up

/tar Val
/castsequence healabunch, healabunch more (I set up macros to get Riptide, Renew, Serenity, etc to roll well if the button gets spammed)

macros for 3 of my toons.

I use the other seven to kill stuff. I just mash the heal button and ignore the portals untill the encounter ends.

One minor thing that helps - spread your three healers slightly and take them off follow so they don't all get hit if the mob with AOE knockup gets his spell off - reduces incoming damage a bit.