Strength Tanks and You.

[Colt47]

But you can swap to DPS stance on that boss when he starts throwing globs to DPS harder in that phase, then pop a CD or two when he stops to get a pseudo tank stance on, and still have DPS stance up to kill the giant green glob before it explodes and DPS stance him some more while he hops around throwing things. When he's done just glance at his HP to decide if you can CD the rest of the fight or if you should go back into tank stance now.

During the glob throwing turning off tank stance shouldn't make any difference to the difficulty the healer has. You're still likely to be a little easier to heal than a DPS if he happens to target you.

Ehhhh, I disagree. When playing tank I don't try to push the healer because, you know, I just want to win, but when I've played healer I've had tanks that purposefully pushed me as I was learning. The most memorable is the guy who did every mob in the swamp of Brayflox normal in 2 or 3 pulls. We had a talk first, he asked how confident I was, suggested he would do huge pulls there and I was like, well, give it a shot. Once or twice he accidentally picked up even more than he meant to.

And that is a perfectly valid time to use sword stance. It's not valid when the boss is just beating on the tank.

As for the second part of your post, there is a difference between consensual testing of yourself and having someone you don't even know completely wing it. A healer doesn't need to be put to the breaking point to learn how to heal right, they just need to be exposed to those unique case situations.