I'll structure my reply in point form because it looks cool and it's easier.
1. Commanding Shout is usable in all stances, the only problem with it is fitting it into a free global cooldown.
2. Shield Block like mad during phase 2. You will probably still get crushed because he attacks so bloody fast though. If you have [item]Moroes' Lucky Pocket Watch[/item], pop it at the start of phase 2 and every time it's up afterwards.
3. I've never thought of using that demon detection elixir to be honest. I haven't needed it, but your mileage may vary.
4. Scorpid Sting = good. Demoralising Shout works against all bosses and should be up at all times, although I can say first hand that it is difficult to do so as the tank. If you have a DPS warrior, have them do it. Don't make them do Thunder Clap if they're Arms or Fury, it wastes way too much rage to stance dance every 30 seconds and hurts their DPS too much. A second Prot warrior could do it though, they generally won't be doing much DPS anyway.
5. Your stats are fine. Just stack on all the usual stam buffs and you'll be set.