That's the setup I'm running right now, level 54 yesterday. There are pros and cons with any kind of healer. I absolutely love disease and poison cleansing totems, it just takes away a whole lot of unnecessary micro. Tremor Totem comes in handy as well, and Earth Shield almost works like a HOT. 5xGift of the Naaru has also saved my ass a number of times. Chain Heal is no Prayer of Healing, but it works well for aoe healing still. I also use Stoneskin Totem when I pull large groups. Got the force of will trinket the other day, so my damage mitigation is stacking up.

Also I have my mages specced frost, and popping 3 water elementals on bosses is also very nice. Just gives alot of free dps with no micro attached. There's gonna be a problem with uneven threat in the later levels I suspect due to dps spiking (one mage critting 3-4 times in a row and effectively threatcapping all your dps), but I'll cross that bridge if I get there.

I have done all bosses in BRD on the lowlevel side of the bar, and I haven't encountered anything that I couldn't beat yet. The arena event gave me a few surprises. Wiped once on the Ogremage cause I didn't remember that he did an arcane explotion. The level 56 or 57 guy in arena who can drop the epic mail chest hit kinda hard, but I lived...barely. And the silencing bats caught me totally off guard, naturally I had forgotten that they aoe silence, so I wiped. I also wiped once on Gerstahn cause I didn't remember that she did an aoe fear. Next time I had Tremor Totem up, and it was pretty easy.