I used a similar build while I played and it worked quite well. My opinion on your build (not that you asked or want it) is throw a weapon skill or 2 in there. I had 2 earthen heart, 2 two handed and 1 draconic power I focused on earthen heart because I like to get to things fast so I think it works out better to focus on one skill line early to get higher skills then branch out as you start to get where you want in the lines you want.
It looks maybe like your build is more PvP than PvE (just a guess) and mine was more PvE oriented, I plan to start the AvA later in the game, maybe not even until I am done the main story line so I am not going to worry about the PvP builds till later and I will just switch skills before entering when I decide to.
For a tanking build I went :
1. Stone Giant (morphed from Stone Fist for the damage shield after use)
2. Brawler (morphed from cleave also for the damage shield)
3. Razor Armor (morphed from Spiked armor for the armor bonus)
4. Osidian Shield (which I would morph to Igneous Shield for the extra armor bonus)
5. Stampede (from Critical Charge morphed for the root effect)
Ultimate was Magma Armor (which I would probably morph to corrosive for the nearby enemy debuff)
For passives I had a few in heavy armor, 2 in the 2 handed line for splash damage and reduced stamina cost 2 in earthen heart for the health buff and increased ability duration for things like the giants fist shield, obsidian and the ultimate. I also had a couple in the Orismer racial line for max health up and health regeneration.
It worked out amazing in the dungeons I got to try, on large number fights I saved mana for obsidian shield and used my Brawler for my personal extra shield and on boss fights I used Stone Giant for boss fights so I could save some stamina for dodging and some blocks though I chose to dodge because I hadn't skilled into any block boosts as of yet (but I plan to). When a harmful enemy got after the healer I had stampede to stop them in their tracks, it worked out really well it was very fun to try different combos of those skills.
I recommend to anyone going into the dungeons as a mellee DD or tank to go close to half and half stamina vs mana skills so you can switch on the fly for whichever resource you will need for a specific fight, this let me completely skill into health and although I was low on both mana and stamina often it was very rare I was unable to use an ability I needed to use at the time.