Warmaster Blackhorn - SURVIVAL is the key

• It's easier to 2-heal than to 3 heal as all P1 damage sources are killable.
• Set sectors of the ship (raid markers really help), assign a ranged or healer to each sector, catching the small shadows
• Shadow catchers (see previous point) & Tanks use prismatic elixir (yes, it stacks with resistance buffs!) + class specific battle elixir INSTEAD of flask.
• Start the fight stacked and stay stacked until the first melee add dies. He can't charge this way and there are no shadows yet. Tanks NEED to face these adds away from the stack.  
• Tanks need to swap which add they are tanking when new adds appear so the debuff drops off.
• At the very start the melee adds are delivered by drakes. The drakes are attackable by ranged.
• Prioritize Sappers>Drakes>Melee Adds
• At the start of P2 melee do not attack Blackhorn!  While Goriona is alive, stand away to "kite" shadows and shockwave. This results in significantly less movement for ranged DPS and healers, also less damage from the boss.
• In P2 after Goriona dies, stack up (healers, casters 10+ yards) and stand in the AoE circles.
• If you are as rich, reroll leatherworker and get +70 shadow res bracer enchant.

This is by no means fully comprehensive, just additional strategies to the onces on icy-veins and such.  

As always, comments are welcome/needed!