I went back and did H Sethekk, messing around for the mount, with my druids when they hit 80. Marginal gear, mostly blues. Owned it. I have wiped there, but because of bad luck pulls, or feared into other adds, etc. Stuff can and will happen, but I can consistently finish that instance. I think the big problem is the gear. At 73, you just won't look significantly different from an ungeared 70, which we know can't do BC heroics, and you're not 80 pimped in abilities yet. Try it again when you've gotten a lot of blues and see if it's not more manageable. BTW, my tank is actually boomkin spec'd and panzerkin geared, so I didn't go in with 30k health and armor and just trash it. It was a pretty honest try. Well, kinda.

The funniest thing is dps burning the first boss with the elemental adds so fast that all 3 elemental spawns occur almost simultaneously and die in a puff.