I find it quite simple, even without misdirects. Once a large ooze is combined, you can get a Shield Slam in before it "activates" and you should have some solid threat to start things off. After that I usually just Thunderclap with the minor glyph. It's enough to keep the aggro and ooze out of range. No need to complicate things.
Definitely. Holding aggro over heals is a breeze. As Charmath said, shield slam it/heroic throw, and keep out of range after they become active. The real fun comes in Keleseth tanking as a warrior. I was in a similar situation with a tank that needed to be "carried" a month or so ago so I took on the difficult jobs. Running around shooting orbs with my gun/heroic throwing was a blast.