The emote, like many others that involve movement, "prefers" not to hit tank classes. They are not immune, they're just not targeted if there are options. The same thing stops silliness at the mephits in PoSmoke raid, and Ralaifins in Prince raid, and several other spots.
Really not a big deal. If your healer gets emoted and you're tanking. Press a button. I think a bigger issue is the summon you thing when he ports, he should properly memblur/drop dots and fade off pets at that stage.
Easy if you're a tank. Kinda sucks for someone else that has to sit on their thumbs and do very little.
The duck emote only checks if you are ducked 10 seconds after it's emoted your name. (sometimes lag extends it by 1 or 2ish) So, you don't have to duck immediately.
They might be a bit bored, but then again, is it not better to be sure to stay alive and not over dps the named?
You only sit on your thumbs for 10 seconds before the next add spawns, at which point you’re dpsing the adds. You’re still very much a contributor to the win and hardly hanging out doing nothing with this strategy.
If you're going for the achievements, the dps needs to be spread out evenly AND the tank needs to hold onto anywhere from 1-4 mobs + AoW at a time. Also, you have to try not to over-dps. It's a fun, well done mission, I think. Once you know not to dot AoW and to pull back pets, its pretty trivial to win. It's slightly harder to do the achievements, but you only need to do those once.